Introduction
The AllegroGraph 6.1.2 Web View (AGWebView) is a graphical user interface for exploring, querying, and managing AllegroGraph repositories. AGWebView uses AllegroGraph's HTTP interface to provide these services through a web browser.
Using AGWebView you can:
- Browse available catalogs and repositories
- Create (also delete) a repository
- Load RDF data into a repository, or into a specific graph of a repository.
- Configure triple indices for a repository
- Set up free-text indexing for a repository
- Issue SPARQL and Prolog queries, which can be saved and reused
- Walk from query results to related triples and resources
- View and add namespaces
- Manage AllegroGraph users and "roles," and their access to repositories
- Capture a query as a web URL for embedding in applications
- Apply Prolog rules and functors to repositories
- Open sessions for commit and rollback.
- Activate RDFS++ reasoning on a repository
- Federate local and remote repositories into a single point of access
- Open telnet connections to AllegroGraph processes for debugging
- View graphs of "construct" and "describe" SPARQL query results
Supported browsers and versions
AGWebView will work with the following browsers on the noted platforms. As with many browser applications, some or all of AGWebView's features may work on other browsers or in other versions, but these have not been tested. In general, we will not fix problems with an earlier version than listed of a supported browser on the platforms noted, but will try to fix problems on later versions released after this list was prepared, if they occur. Sometimes a new version of AllegroGraph is needed so that AGWebView will work with a new version of a browser.
Browser | Earliest Supported Version | On Platforms |
---|---|---|
Chrome | 40.0.2214 | Mac OS X, Windows, Linux |
Firefox | 38.0 | Mac OS X, Windows, Linux |
Internet Explorer | 11 | Windows |
Safari | 7.1 | Mac OS X |
Starting AGWebView
AGWebView is a part of AllegroGraph server. When the server is running, AGWebView may be opened by typing the server's IP address and port number into the address field of a web browser:
http://localhost:10035
Logging in
If there is an AllegroGraph server listening on that port, AGWebView will respond immediately with a login form:
If you are exploring AGWebView for the first time, log in using the name and password of the AllegroGraph superuser you created during server installation. In Franz's documentation this user is usually described as "test" with password "xyzzy".
Once logged in you can create additional user accounts with different types of access and privileges.
Data Display Conventions
Much of the AGWebView interface is concerned with the "parts" of triples, which are composed of Uniform Resource Identifiers (URIs) and literal values.
In AGWebView, URIs consist of a namespace and a local name enclosed in angle-brackets <>.
<http://franz.com/examples#Alice>
where http://franz.com/examples# is the namespace, and Alice is the local name.
By default, the AGWebView interface removes the namespace and displays only the local name. This produces query results that are easy to read:
For more detail, you can use a checkbox in the upper right corner of the AGWebView screen to turn on the "long parts" feature to see the full URIs:
AllegroGraph supports many types of literal values, as shown in our java tutorial. Literals generally appear as quoted strings in the AGWebView interface:
The "42" in the above image looks like a string but it is actually a xsd:long (a high-precision integer). To see the types of your literals, invoke the "long parts" feature again:
Managing Namespaces
The difference between the "short parts" and "long parts" displays shown above is the suppression of the URI namespace in the condensed displays. This makes the output easier to read.
We can also use namespaces for input. To make it easier to type in lengthy URIs, AllegroGraph provide a set of shared namespace abbreviations. These namespaces make it much easier to set up queries or to assert new triples by hand. These are the shared namespaces in AGWebView:
rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
rdfs: <http://www.w3.org/2000/01/rdf-schema#>
owl: <http://www.w3.org/2002/07/owl#>
dc: <http://purl.org/dc/elements/1.1/>
dcterms: <http://purl.org/dc/terms/>
foaf: <http://xmlns.com/foaf/0.1/>
fti: <http://franz.com/ns/allegrograph/2.2/textindex/>
skos: <http://www.w3.org/2004/02/skos/core#>
These namespaces are available to every user in every repository.
In addition to the shared namespaces, you can create custom namespaces in a repository. Some of these are shared, meaning that any user with access to the repository can use them. There are also private namespaces that are available only to a single user.
The list of namespaces is displayed by the Utilities | Namespaces menu choice when on a Repository page.
This displays the list of all available namespaces, whether they are in use or not. The define a user namespace and define a repository namespace links below the lists let you add a new namespaces.
You can also display the list of namespaces on the New Query page of a repository. Look for the "Show namespaces" link to the right. This is the list of shared and private namespaces that are available to that query. On this page the "add a namespace" link lets you create a new private namespace owned by the current user.
To create a namespace, simply click one of the "define namespace" links and then fill out the form:
Then to use the namespace, type it into an input field with the required colon (:) and the local name of the resource.
AGWebView will automatically expand the full URIs behind the scenes.
Modifying a namespace: If you wish to modify a namespace, so that a prefix expands to a different value, you must delete it first (there are Delete buttons next the namespaces when you display with the Namespaces choice on the Utilities menu) and then add it back with the revised value. It is an error to try to add a namespace with a prefix already in use.
Managing Users
See Security for more information on this topic (much of the information presented here about managing users is repeated in that document).
To open an AllegroGraph repository, you must supply an AllegroGraph user name and password. AllegroGraph users can differ in terms of repository access, ability to manage other user accounts, and permission to create sessions and to run arbitrary code.
This section describes user-related tasks and how to perform them. Many of these tasks can be performed on the User Management page. See the description of that page for a list of the controls found on it.
Initial Superuser
An initial superuser is created during the AllegroGraph server installation. This user typically appears in Franz documentation as user "test", password "xyzzy". Examples will show that user and password.
This superuser can create and manage other users, can start sessions, can evaluate arbitrary code. The superuser (and any superuser created subsequently) may not initially have access to any repositories (depending on the value of the SuperUserCanAccessAllData
configuration option described in Server Configuration and Control). But even if access is not initially granted, any superuser can add access to any or all repositories by editing the their profile on the Users page. Such additions will, however, be logged when auditing is enabled.
Note that you want to have at least one superuser at all times, because only an AllegroGraph superuser can manage permissions and access for other accounts. It is possible to delete the last superuser and lock yourself out of user management, which is embarrassing but not fatal. You can re-create the original superuser by re-running the AllegroGraph server configuration script. This step has no impact on other user accounts.
Create a New User
Superusers can access the User Management page by choosing Users from the Admin menu.
Note that only superusers will see an Admin menu or be able to access the User Management page.
Once there, current users and roles are listed (we have created a role called BackupOperator). You can create a new user by clicking the [add a user] link. This opens a form for the user name and password of the new user:
User names and passwords are case-sensitive. New passwords may have restrictions such as minimum number of characters, minimum number of uppercase letters, and minimum number of non-alphanumeric characters. Except for the user anonymous, you are not allowed to create a user without also specifying a password.
We have created a user mikel. Once a user is added, you can click on edit to modify what the user can do.
Set Permissions
You can specify permissions by clicking on the [edit] link next to the new user's name on the User Management page. You will see four checkboxes:
A Superuser may not automatically have all possible permissions and unlimited access. A superuser can create, manage and delete other user accounts. Non-superusers cannot view or edit account settings. (The superuser without permissions can give him/herself any permissions desired but such changes are logged if auditing is enabled -- see Audit.html).
A user with the Start Sessions permission can use the AllegroGraph features that require spawning a dedicated session, such as Transactions and Social Network Analysis (SNA). If you try to use these features without the appropriate permission, you'll encounter authorization errors. This permission should be withheld from users who do not need it because it spawns back-end processes that occupy memory and consume CPU cycles.
A user with permission to Evaluate Arbitrary Code can run Prolog "select" queries. This user can also do anything else that allows executing Lisp code, such as defining Prolog select generators for SNA, or doing eval-in-server, as well as loading server-side files. This permission should be withheld from users who are not fully trusted and even among trusted users, it should be granted only to those who need it. The ability to evaluate code in the hands of a knowledgeable user is equivalent to superuser privileges.
The Control Replication permission allows a user to set up automatic replication of a repository across multiple servers. This facilitates AllegroGraph's replication and point-in-time recovery features.
Access Control
You might want to limit a user's access to your repositories and catalogs. The Access Control form lets you do that.
Immediately under the permissions checkboxes you will find the Access Control form:
Select the access (read, write or both) and then select the catalog and repository. Asterisk (*) behaves as a wildcard in these fields. The forward slash (/) designates the root catalog. Click the "OK" link to add this permission. You can use the form repeatedly to add multiple permissions.
You will see the new permissions listed on the screen, just above the Access Control form:
The "remove" link deletes the permission.
Filtering out triples
You can set up filters which limit access to specific triples (those with specified subject, predicate, object, or graph). See the discussion of Security filtering in Security Implementation for more information.
Managing Roles
A "role" is a predefined set of permissions and access settings. Roles let us centrally manage the permissions and access of a class of users. Security experts prefer to manage access through roles because it lets them respond quickly to an emergency. A single mouse-click on a role can revoke permissions from scores of users at the same time. To make the same change in all the individual user accounts would take too much time.
To create a role, go to the User Management page and scroll down to the Roles section. Click the "add a role" link. Enter the name of the new role in the resulting form. Note that role names should be descriptive and specific, because they become entries on a potentially long list of available roles.
Once the role has been created, give it permissions and access just as if it were a user account.
To apply a role to a user account, click the "edit" link for that account.
Select the role from the list and click the "OK" link. The user's local permissions and access indicators will not change, but he/she will have the full powers of the role.
Anonymous Access
If you create a user named "anonymous" (the case is significant, all lowercase), AGWebView will enable anonymous login. This is the only user account that can be created without a password.
On the User Management page, click the "add a user" link and type "anonymous" in the __Username__ field. Then click the "OK" button.
From this point on, AGWebView will automatically log in the anonymous user each time you connect to the server. This makes AGWebView available to anyone, but only within the limits imposed by the permissions and access settings of the anonymous account. Be sure to give the anonymous account read access to at least one repository or the visitors won't be able to see anything.
Anonymous access does not prevent you from logging in as another user. Look for the "User: anonymous > login" menu item in order to log in to your account.
Self-Enrollment
AGWebView can permit otherwise anonymous users to self-enroll by registering usernames and passwords for themselves. These self-enrolled users have the same permissions and access as the anonymous user, but they can also have private namespaces and their own saved queries.
A superuser enables this feature in the Site Settings section of the Root Catalog page, by clicking the "Allow" link.
When self-registration is allowed, there is a "User anonymous > register" menu item in the page banner. This link opens a form for creating a new user. The new user is automatically logged in after registration.
SPARQL Queries
The reader might appreciate some "seed" queries to help get started with SPARQL. Note the use of curly braces {} instead of parentheses () in SPARQL queries.
"Show the subject and object values from fifty rdf:type triples." This returns only the values you ask for.
select ?s ?o where {?s rdf:type ?o} limit 50
"Construct fifty new triples from values found in existing triples." This returns a set of actual triples, sometimes called a "graph."
construct {?s ?p ?o} where {?s ?p ?o} limit 50
"Describe a resource to me." Note that this query returns all triples that describe a specific resource, including those obtained by traversing a blank node.
describe ?s where {?s ?p ?o} limit 1
Prolog Queries
The user account must have permission to "execute arbitrary code" in order to execute a Prolog query.
AllegroGraph provides "select" queries as an extension to its internal Prolog language. This is a simple Prolog query. Note the use of parentheses () instead of curly braces {}, and that the triple patterns begins with a "q". Also, namespace abbreviations must be preceded by a bang (!) character.
(select (?s ?o) (:limit 10) (q ?s !rdf:type ?o) )
This query returns subject and object values for ten triples that contain an rdf:type predicate.
Prolog "select" queries are the portal to AllegroGraph's geospatial and social-network features.
Session Specifications
The AGWebView interface allows the advanced user to create a new "session." It offers you an empty text field (on the Root Catalog page) to enter your "session specification."
This is a powerful tool for creating complex federated repositories, with reasoning and graph filtering applied to the individual repositories of the federation.
For instance, this specification federates a reasoning version of repository "A" in the root catalog with a reasoning version of the "http://example.com/graph1" graph of repository "B" in the "public" catalog:
<A>[rdfs++] + <public:B>{<http://example.com/graph1>}[rdfs++]
In a session specification, local repositories are written as <catalog:name>, or just <name> for repositories in the root catalog.
Remote repositories are written by putting their URL between < and >.
Multiple repositories can be federated by putting plus signs (+) between them. For example, <repository1> + <repository2>.
To apply a reasoner to a repository, write [rdfs++] or [hasvalue] after it.
To create a filtered repository, write the URIs of the participating graphs between braces {}, using null to indicate the default graph.
The Session Specification field has an "autocommit" checkbox next to it. Uncheck this box to create transaction semantics, where you can manually issue "commit" and "rollback" actions as needed. Look for them in the Session menu, up in the page banner. Note that with the optional Sesame 2.7 transaction handling semantics, autocommit reverts to true after a "commit" or a "rollback".
Free-Text Indices
AllegroGraph supports multiple free-text indices, each targeted as narrowly as you like on specific fields of specific predicates.
The form for creating a free-text index is on the Free-Text Indices page.
Each free-text index has a name, so you can apply it to a query or perform maintenance on it.
Each index works with one or more specific predicates, including an option to index all predicates.
An index can include all literals, no literals, or specific types of literals.
An index can process the full URI of a resource, just the local name of the resource (after the # or /), or it can ignore resource URIs entirely.
An index can focus on any combination of the four parts of a "triple:" the subject, predicate, object, and graph.
Stop words (ignored words) may be specified, or the index can use a default list of stop words.
In addition, an index can make use of word filters such as stem.english or drop-accents.
WebView User Interface
This section provides a page-by-page summary of the AGWebView user interface.
Banner
There is a blue header across the top of most AGWebView pages. This banner displays the name of the logged-in user and offers context-specific controls that let you "back out" to previous pages or to access general functions such as "logout". The illustration just shows a possible banner. Because available choices are displayed according to the context, not all choices are shown in this illustration, and some that are shown, you may not see. You will see other banners in other illustrations.
- (Backarrow)
- The curly backarrow symbol lets you go back a level in the hierarchy of AGWebView pages.
- Repository
- This choice returns you to the current repository page.
- Queries
- This choice displays a menu of query choices, including:
- New: Display the Query page
- Saved: Display saved queries, if any
- Recent: Display recent queries
- Free text: Allow searches in free text indices, if any
- Utilities
- This dropdown menu gives access to various utilities. Some choices may be grayed out (and thus non-operational) if they do not apply. Choices include
- Scripts: This link displays Server Scripting page. Only users with Eval access will see this item (see the Evaluate Arbitrary Code user permission in the Set Permissions section of the Managing Users section for information on Eval access). This allows loading or defining User scripts and Site scripts. See the Scripting the server section in the REST/HTTP interface document for information on scripting.
- Namespaces: This link displays the Namespace Selection page.
- Geospatial Datatype Designer: This link opens the Geospatial Datatype Designer page (see the WebView Geospatial Datatype Designer section in the N-dimensional Geospatial Usage Guide and Example document.
- Settings: This link displays a settings page. See the settings page.
- Admin
- This is a drop-down menu offering various options to the AllegroGraph superuser only (non-superusers do not see this menu):
- Users: This link opens the User Management page.
- Jobs: This link opens the jobs page.
- Audit log: This link opens the audit page.
- View server log: This link opens the server log.
- View server configuration: This link opens the configuration file (see Server Configuration and Control).
- View/edit initfile: This link opens the Initfile editing page.
- Processes: This link opens the Processes page.
- User
- This is a menu that drops down from the name of the current user offering:
- change password
- logout: The current user logs out.
- delete: The current user has an opportunity to delete his/her own account.
- Session
- When you have opened a transaction session in a repository, a session menu appears in the banner.
- commit lets you take all of the triples you have loaded or created up to this point, and add them permanently to the repository.
- rollback lets you discard all uncommitted triples, presumably because your load was interrupted and you want to start over.
- close terminates the session.
The settings page
The settings page is displayed when you select the Utilities | Settings menu choice. There are two tabs. The Server tab:
This tab displays information about the server and also allows you to specify a message to be displayed when the system detects that a large operation has been requested. Large operations are backup, data export, and query download. The warning message is displayed for all those operations.
Here we add a large operation warning (About to perform a large operation!!!):
Then, when we execute a query and click on the Download button at the bottom, the warning is displayed and the user is offered the opportunity to cancel the operation:
If the large operation warning is blank (as it is initially and is if all text is deleted from the settings box), no warning is displayed and the user is not given to opportunity to cancel.
Here is the Browser Session tab:
This tab displays browser display options, including whether to display full URIs and whether to show contexts.
User Management Page
Superusers can access the User Management page by choosing Users from the Admin menu.
See the Managing Users section for a task-based explanation of user management.
The User Management page lists users and roles (in the illustration, there are two users, test and anonymous, and no roles). There are links to add, edit, and delete users. Clicking on edit displays the following:
Again, see the Managing Users section for an explanation of the various choices.
Root Catalog Page
The Root Catalog page is the top-level page for the AGWebView interface. We call it the "Root Catalog" page because it lists the repositories of the root catalog. It also lists the names of any named (non-root) catalogs that are present. This page lets you choose a repository to manage.
This is the page you see when you log into AGWebView. Later you can return to this page by clicking the "<<" link in the page banner until the focus returns to the top level.
- Catalogs
- These are the non-root catalogs of the system. Click on one to see the repositories it contains.
- Repositories
- These are the repositories of the root catalog.
- Create a Repository
- Create a new repository in the root catalog. Note the repository name cannot contain any of the following characters:
\ / ~ : Space $ { } < > * + [ ] |
- Start session
- This field lets you create an arbitrarily complex federated repository. See Session Specification earlier in this document.
Named Catalog Page
From the top-level Root Catalog page, click on any non-root catalog. This opens a Named Catalog page. This page lists all the repositories that are available within that catalog. Note that this page has the name of a specific catalog at the top (tests in the illustration.).
The various links include:
- Repositories
- These are the available repositories within this catalog. Clicking on one displays its Repository Overview page.
- Create a Repository
- Create a new repository in the current catalog.
- Start session
- This field lets you create an arbitrarily complex federated repository. See Session Specifications earlier in this document.
Repository Overview Page
The Repository Overview page gives you access to a specific repository within a specific catalog. The name of the repository is posted at the top of the page and again under the banner. The catalog, if it is not the root catalog, is also shown under the banner (tests in the illustration).
Edit Description
This link lets you create a brief text description of the repository.
Load and Delete Data
This group of choices allows you to add or triples.
- Add a Statement
- This link opens a form to let you enter the subject, predicate, and object URIs of a new triple. You may optionally add a context (graph) URI. There is a drop-down list of existing graphs. You may also add attributes. Attributes must be defined in the repository before being used. See Define attribute definitions below. Attributes must be specified using JSON object syntax. The illustration shows an example.
- Delete Statements
- Enter any combination of URIs, wildcards, and literals into the fields of the form. Click OK to delete all matching statements from the repository. Caution: There is no way to undo this action.
- Import RDF
- The choices allow you to select a file and load it into the repository. It can be a local file or a server-side file. The dialog displayed by the from an uploaded file choice is displayed below. If you click the Choose Files button, the file choice dialog initially displays the server installation directory's tutorial/ subdirectory (if it is in the expected place -- otherwise it displays the installation directory itself). Subsequent invocations display the last directory from which a file was loaded. See the tutorial directory section in AllegroGraph Quick Start for more information on the initial directory that will be displayed. The dialog displayed by the from a server-side file is similar except instead of a Choose Files button, it shows a widget showing the server-side directories and files.
The dialog has many options, many associated with options to the agload utility, described in the Data Loading document. Pop-up tooltips appear when you mouse over many of the options. Note that agload will be used when you select the Using agload file loading mode and but not when you select Transactional but the meaning of the other options is the same in either case. If you select Using agload, you can then specify how many agload processes will run. This specifies a value for the --loaders option to agload.
If you select Transactional, then the triples will be inserted within a single atomic transaction, which will either succeed completely or fail completely. This is suitable for small operations but not recommended for large data loads. agload loads and commits triples in batches so when it fails, some but not all triples will typically have loaded and committed. See the Data Loading document for more information on this point.
The options include:
format: the format of the data in the file. Choices include N-Triples, N-Quads, NQX (extended N-Quads with attributes), RDF/XML, Trix, TriG, and Turtle. See the input option to agload for more information. The default is Autodetect, which means get the format from the file extension (so an extension of ntriples or nt means an N-Triples file).
Context: the default graph for the triples being loaded if it is not otherwise specified (as it is in N-Quads).
Attributes: you can specify attributes which will be added to every triple which does not have attributes specified in the file (see the --attributes option to agload). Only NQX files can have attributes specified, so the attributes specified here are added to every triple in files other than NQX files. Attributes must be defined in the repository before being used. See Define attribute definitions below. Attributes must be specified in JSON format, such as
{"bar": "high"}
. See the Triple Attributes document for more information.Relax syntax: see the relax-syntax option to agload. If selected, data which looks okay but is in fact improper RDF (for example, contains trailing spaces or hyphens in blank node ids) will be accepted. We recommend correcting your data files so they are proper RDF, but this option is useful during development or when demo-ing so that nearly correct data can be loaded.
File loading mode: Multi-core uses agload and is possibly faster. Single-threaded means use one core only and a simpler loading program.
Error handling: see the error-strategy option to agload. Cancel load means if an error is encountered, cancel the load. Note that triples already loaded will not be removed. Ignore errors will attempt to continue upon an error, so if one triple is mangled, it will be skipped but the remaining will be loaded, if possible.
Use bulk load mode: see the bulk option to agload. Enable bulk mode while processing the loading job. Bulk mode turns off transaction log processing and can provide considerable performance gain for large jobs. Warning: transaction log processing is turned off for the entire database (not just you loading this file). Other users may be affected. The database may be irrecoverably corrupted if something goes wrong. Use this option with care!
Explore the Repository
These choices allow you to view triples in the repository.
- View Statements
- This link runs an unrestricted SPARQL query and returns the first 100 triples it finds. The purpose of this feature is to give you a quick look into the repository.
- View repository's classes
- This is another feature that lets you take a quick look at a new repository. It runs a SPARQL query that lists the rdf:type classes in the repository.
- View repository's predicates
- This feature runs a SPARQL query that lists the first 100 predicates found in the repository.
Repository Control
The choices for manipulating a repository include the following. Many choices call functions in the Lisp API which are linked to.
- Export
- You can dump the repository to a file, using any of these RDF formats:
- N-Triples
- N-Quads
- NQX
- RDF/XML
- TriX
- Turtle
- Start a Session
- This link starts a dedicated session in this repository, which establishes transaction semantics. A Session menu will appear in the banner, offering Commit and Rollback links. Commit lets you take all of the triples you have loaded or created up to this point, and add them permanently to the repository. Rollback lets you discard all uncommitted triples, presumably because the load was interrupted and you want to start over. The menu also offers a Close link, which ends the session.
- Control Replication
- See the document on Replication and Warm Standby. See also Replication below.
- Back-up this repository
- Initiate a backup.
- Purge deleted triples
- See Purging Deleted Triples. Removes inaccessible triples from indices. Only available to superusers.
- Export duplicate statements
- Serializes a list of duplicate triples to a file in Nquads format. The duplicates can be SPO-identical (ignoring the graph) or SPOG-identical (considering the graph). Triples not visible to the current user will not be written. The triples written to the file will be the triples deleted if duplicates are deleted (prior to the next commit, which may change what are and what are not duplicates). See Deleting Duplicate Triples.
- Delete duplicate statements
- Performs a one-time removal of duplicates from the repository. A pop-up window allows you to chose whether two triples that share subject/predicate/object (spo) are considered duplicates or only triples that share subject/predicate/object/graph (spog).
- See Deleting Duplicate Triples.
- Suppress duplicate statements
- Set the duplicate suppression strategy. That instructs AllegroGraph about triples being committed. The choices are ignore duplicates, suppress (i.e. delete) duplicates which share subject/predicate/object (spo), or suppress duplicates which share subject/predicate/object/graph (spog). Already committed triples are not affected by this command. See delete-duplicate-triples.
- Optimize the repository
- When clicked, the repository is optimized. Adding new triples or deleting existing ones slows things down after optimization, so you typically optimize when you are not adding or deleting triples, and re-optimize after later additions or deletions. Optimizing will organize and index the existing triples for optimal query performance. Enabling may take a long time on big repositories; [running] is displayed after the link while optimization is going on and disappears when complete. (It is not an error to add or delete triples which optimization is going on, it just reduces the effect of optimization.) See optimize-indices. Clicking this option optimizes at level 2.
- Recognize geospatial datatypes automatically
- If checked, then when triples are being added from an external source (e.g. a N-triples file or a SPARQL INSERT), the loader will check whether the leading portion of the type URI matches an AllegroGraph geospatial type. (Both the old 2D and new nD types are checked.) If so, and if the type has not yet been encountered in this repository, the subtype is reconstructed from the type string and automatic predicate and datatype mappings are added to the repository. See The WebView Geospatial Datatype Designer in the N-dimensional Geospatial Usage Guide and Example document for details.
- Control durability (bulk-load mode)
- If bulk-load mode is turned on, logging of modifications to the repository is suppressed and so, at a minimum, full recovery is not possible in case of an AllegroGraph or system crash (as unlogged modifications cannot be recovered). Loading of triples is consequently faster. Use care when enabling bulk-load mode. A crash while in bulk mode will likely result in an irreparably corrupted database, in which case restoration from a backup will be necessary. Be prepared for that possibility if you enable bulk-load mode. Clicking on this option displays the current mode and allows you to change it.
- Define attribute definitions
- Displays a dialog which allows you to define attributes (you must have superuser privileges). When first displayed, only the buttons (Add New, Save, and Revert) and the documentation appear. Clicking on Add New displays fields to fill in, as shown in the illustration. The documentation text describes how to input a definition. See the Defining attributes section for information on the various options. See the Attributes example below for more information.
- Set static attribute filter
- Displays a dialog which shows the current static attribute filter, if any, and allows adding a filter or editing the existing filter. See the Attributes example below for more information.
- Active Indices
- This is the list of active triple indices for this repository. Click on an "x" icon to delete an index, or use the Add Index link to add one.
- Manage free-text indices
- This link takes you to the Free-Text Indices page. See the section on Free-Text Indexing, above. Once you have created a free-text index, you can use the Queries menu to initiate a text search.
- Materialize Entailed Triples
- When you click on Materialize Entailed Triples, you will get a dialog at the top of the screen which allows you to enter specifications for materialization. Each of the fields has help text. When materialization is done, a message is added to the message area which reports the number of materialized triples added. See Materializer for information on materialization.
- Delete Materialized Triples
- Deletes any previously materialized triples. Upon completion it reports in the message area the number of triples removed.
- Manage external Solr free-text indexer
- This link lets you set up a connection to the Apache Solr full-text indexer from an AllegroGraph repository. See Solr Text Index.
- Manage external MongoDB connection
- This link lets you set up a connection to a MongoDB from an AllegroGraph repository. See MongoDB interface.
Free-Text Indices Page
One reaches the Free-Text Indices page by clicking "Manage free-text indices" on the Repository Overview page.
This displays the Free-text indices page for the repository. In the illustration, we have one such index, named myindex, which we created by accepting all the default values and settings.
To create a new index, type its name into the field at the bottom (indicated by the red arrow). Remember that there might be many indices, so the name should be fairly specific. We have chosen the name long-word-index (because we only index words 10 characters or more long -- see the Minimum word length field indicated by the red arrow in the dialog below). Click the "Create" link and the following dialog is displayed:
See the Free-Text Indices section for a discussion of the various options. Click OK at the bottom to create the index.
When you create a new index or edit the parameters of an old one, AllegroGraph will reload the triples to bring the index up to date.
An example of defining attributes and static filters
There is a general attributes/static filter example found in java-tutorial/AttributesExample.java. Currently, all that can be done in WebView is define attributes and static filters. Currently in AGWebView there is no way to associate attributes with a user. Thus if a static filter restricts access to triples, no user can see those triples in AGWebView. They can be seen using other tools, as the Java example shows.
Further, if an attribute is defined with Minimum number greater than 0, then no triple can be loaded into the repository without that attribute having a value (actually, the required number of values).
These two lines from the repository view have to do with attributes and static filters:
Clicking on Define attribute definitions displays a dialog which allows attribute definitions. Here we have filled in the fields from the example referenced above:
Because securityLevel
has min and max 1, there must be exactly one of these attributes for every added triple.
Similarly, clicking on Set static attribute filter displays a dialog allowing the filters to be defined. Here we define the filter from the example:
We pasted the definition into the Edit filter area and clicked on Save, and it appeared in the Current filter area.
New Query Page
From the Repository Overview page, click the New link in the Queries menu. This exposes a page where you can edit a SPARQL or Prolog query to run against this repository.
See the sections on SPARQL Queries and Prolog Queries for example queries to get you started.
This page lets you edit a new SPARQL or Prolog query and test it against the repository. The query (as shown below) goes in the (blank in the first picture) Edit Query field. The various options and buttons work as follows. Note that Anonymous users do not have all options and may not see what a regular user sees.
Results are displayed under the Edit Query field, as illustrated below.
- Language
- The Query page accepts SPARQL queries from all users. Users with permission to execute arbitrary code also have the option of issuing Prolog queries.
- Planner
- The choices are Default, Statistical, Identity, and Weak-identity.
- Result limit_
- This choice specifies how may results to display. Note that this value overrides a LIMIT specified in the query, so
SELECT ?s ?p ?o {?s ?p ?o} LIMIT 1
- will display up to the number of results in this box (default is 100) rather than at most 1 result. In general, the outermost handler (AGWebView in this case) determines things like LIMIT.
- Reasoning, Long parts, Contexts check boxes
- When checked, enable reasoning, display full URIs when showing parts, and show graph names, respectively.
- Show namespaces
- Click this link to view the table of namespaces that are available to the current query. This could be a mix of shared and private namespaces.
- Add a namespace
- This link lets you enter a new, private namespace to use in this query. When you click this link, the following embedded dialog is displayed, allowing you to enter the namespace prefix and URI. The Bulk Input button allows you to enter multiple namespaces at once. Click this button to open an edit field where you can paste in many namespaces in one operation. Use one namespace per line, in a format like "ex http://example.com/" or "ex: http://example.com/". (Note that bulk is used by two utilities in different ways. In data loading (see Data Loading), bulk means loading data without transaction logging. In Sesame and Jena and also here it mean processing several statements at once but is not related to transaction logging or loading.)
- Modifying a namespace: If you wish to modify a namespace, so that a prefix expands to a different value, you must delete it first (there are Delete buttons next the namespaces when you display with the Namespaces choice on the Utilities menu) and then add it back with the revised value. It is an error to try to add a namespace with a prefix already in use.
- copy link to query
- Click this link to generate a URL that invokes this query on this repository. You can publish this URL or embed it in software. Copy the URL from the browser's address field. Note that this URL requires anonymous access. If there is no anonymous account, AGWebView will require the user to log in.
The button along the bottom are:
- Execute
- The Execute button runs the query. A table of results will appear in the lower half of the page.
- Log Query
- Clicking this button executes the query and then displays information about the operation of the query. Note the query results are not displayed nor otherwise made available. To see them, you must click Execute.
- Show Plan
- Displays the query plan is the results area. The plan is pseudo-code which explains the process by which the query will be answered. There is an example below.
- Save As
- You can save a private copy of a query for later reuse. Give it a name and then click the Save button. To find this query again, click the saved link in the Queries menu in the page banner. The *Saved* choice only appears if there are saved queries.
(This feature is available to superusers, normal users, and self-registered users, but not to anonymous users.) - Add to Repository
- You can also "save" a query by adding it to the Repository Overview page as a link to a "Pre-defined Query." To do this, give the query a name and click the "Add to Repository" button. (Superusers can add a query to the Repository Overview page. All users, including anonymous, can then use it.)
- Edit Initfile
- This feature is available only to superusers. The "edit initfile" link opens a large edit field containing the text of the AllegroGraph server's initialization file, which is
/data/settings/initfile.
This code is run by AllegroGraph server each time a new session is opened. It lets you load Prolog functor definitions to use with your Prolog queries.
The Result field
Results are displayed in a table. Each URI in the table is a link to a page of information about how that URI is used in the repository.
- Download as
- If your query produced triples as output (such as a SPARQL "construct" or "describe" query does), then this feature lets you save the results in one of four formats: N-Triples, N-Quads, RDF/XML, or TriX. If the results are just a list of variable values, like a SPARQL "select" query creates, you can choose between the SPARQL XML Result format and a comma-separate list of values.
The Cancel button
While a query is running, you see the word Loading and a spinning dots icon. Also, a Cancel button appears. You can click this button to stop the query. Stopping may take a few seconds. No results found will appear in the Results area when the query is stopped.
Specialized result options
- Display Geospatial Data on a Map
- If the search results contain AllegroGraph geospatial coordinates, and if you have provided AGWebView with a Google Maps key, then AGWebView will offer to display the query results as a map. See the section about Google Maps.
- View Results as Graph
- When you execute a SPARQL "construct" or "describe" query, the result is a set of actual triples that can be displayed as a graph. Click this link to display the graph. In the graph, blue nodes are resources and green ones are literal values. Hover the mouse over a node to see a description of the node. (This description appears as text on the line above the graph, not directly above the node.) Similarly, the arrowheads on the lines between nodes reveal the name of a predicate. You can drag the nodes around on the screen and watch the graph adjust to a new equilibrium.
Saved Query Page
If you have saved named queries on the New Query page, you can retrieve them by clicking the saved link of the Queries menu in the page banner. This produces a list of your saved queries.
Note that each query in the list is followed by a small "x" character. Click this "x" to delete the query.
Recent Query Page
The Recent Query page contains a list of your recently-executed queries, which includes your saved queries plus any other queries you ran.
Click on an entry in the list to re-run the query.
Text Query Page
The Text Query page is a free-text search form. You get to select the text index to use. If you have not created any text indices, the page will prompt you to do so. Searching here produces a table of matching triples.
Processes Page
This page lists the AllegroGraph processes that are currently running. It is used for debugging AllegroGraph behavior.
To reach this page, click the "Processes" link in Admin menu of the page banner. AllegroGraph can create many subprocesses.
- stacktrace
- This link displays the stacktrace of the process.
- kill
- This link kills the process.
- start telnet
- This link opens a telnet port directly into the eval command loop of the process. This lets an engineer interact directly with the process for diagnostic purposes.
Namespace Selection Page
- My namespaces
- These are namespaces that you have entered in the current repository for your personal use. Add namespace lets you add another namespace to the repository. The "x" icon after a namespace name lets you delete it from the repository.
- Standard namespaces
- These are the namespaces for this repository that are shared among users. Use the checkboxes to the left to enable or disable individual namespaces for this repository.
Replication Page
See the document on Replication and Warm Standby. If there is an active replication server available, this page lets you connect to it and set up a warm-standby repository on the local server.
Auditing page
When auditing is enabled, AllegroGraph provides a structured system audit log which tracks important changes to the server and its repositories. This log is useful for system and database administrators conscious of security and performance.
Auditing is not enabled by default. In order to enable auditing (which must happen when the server is started), add the following line to the agraph.cfg file:
Auditing yes
See Server Configuration for further information on the configuration file. Note that the Audit menu item and page described below will appear even when auditing is disabled, and information collected in previous runs with auditing enabled (and thus written to the audit log) may be displayed, but no new information will be stored when auditing is disabled.
In what follows, we assume auditing is enabled. Auditing is also discussed in the Auditing document, where the example below is repeated.
You can use the AG WebView interface to examine auditing information. Only superusers can look at the auditing information. There is an audit log entry on the Admin menu on the WebView menu bar, as shown in the illustration:
If selected, the following page is displayed:
No information is displayed because we have not requested any (and, in fact, the page was displayed immediately after a fresh startup so there is no information to display).
After we have, as superuser super, added two users (fred and joe), the updated page (looking at actions by super, as super is selected, and event add user) shows when those users were added and by whom. Information is refreshed when the View Audit Log button is clicked.
The multi-item widgets User names and Event types allow you to filter audit log entries by user and event type. Multiple items can be selected from each list. Clicking All under each list selects all items. The standard combinations of mouse clicks and the Control and Shift keys can be used to select individual or groups of items.
The two date boxes to the right allow restricting displayed log entries to a range of dates.
Next user joe creates and deletes a repository asia and creates a repository kennedy, to which he adds a bunch of triples, and super (the superuser) modifies joe's user permissions several times. Here are screens after that activity, the first showing all activity and the second just the change user activity of super. Again, clicking View Audit Log clears the currently displayed information and displays information based on the selections in the various lists and boxes.
User joe did add triples to the kennedy repository, but the audit log does not record adding and deleting triples so that activity is not shown.