Virtuoso Tips and Tricks
We have a number of tips and tricks articles, covering various areas of Virtuoso functionality.
Database Administration
- How can I specify an OS user name to which the Virtuoso server will switch after opening the listen ports??
- How can I find out which tables are deadlocking??
- How can I configure parameters to avoid out of memory errors??
- How can I control normalization of UNICODE3 accented chars in the free-text index??
- What should I do if the Virtuoso Server is not responding to HTTP requests??
- How can I perform a checkpoint against a clustered Virtuoso Server??
- How can I handle checkpoint condition??
- How can I backup and restore individual table(s) and individual index(s) on a a new fresh db??
- How Do I Generate Transient and/or Persistent Linked Data Views atop ODBC or JDBC accessible Relational Data Sources??
- How Can I perform SQL login with X 509 WebID watermarked certificate??
- How do I recover from "Invalid log entry in replay" when transaction log is being replayed during server start?
- How can I move a Virtuoso database from one hardware and/or software platform to another??
- What should I do if the Virtuoso Server is not responding to HTTP requests??
- How can I set up Virtuoso Lite Mode??
- How can I use the LD Meter Utility??
- How to proxy Virtuoso HTTP server through Apache HTTP server front end??
- How to configure Virtuoso Cluster slave nodes HTTP listeners??
- How to configure Virtuoso Elastic Cluster??
- How to Monitor Virtuoso Memory Consumption??
RDF data management
- How can I obtain a list of all graphs??
- How to manage Graph Security Level for SQL Clients??
- How can I test whether two graphs are equal?
- How can I add triples to a graph?
- How can I update triples in a graph?
- How can I delete triples from a graph?
- How can I delete triples from a "Large" graph??
- How Can I Delete Triples containing blank nodes??
- How can I copy triples from one graph to another?
- How can I move triples from one graph to another?
- How can I drop a graph?
- What is the difference between "DELETE FROM GRAPH" and "CLEAR GRAPH"?
- How can I drop a graph for which is not clear was it created explicitly or not??
- How can I perform RDF dumps from Virtuoso Quad store hosted data??
- How can I perform Dump of RDF Graphs into NQuad dumps??
- How can I delete graphs using stored procedure??
- How Can I Delete Triple Patterns that are not scoped to a named graph??
- What are the differences between create, drop, clear and delete Graph??
- What are "Generate RDB2RDF triggers" and "Enable Data Syncs with Physical Quad Store" Linked Data Views options??
- How Can I Diagnose problems associated with Linked Data views generation??
- How can I display only some information from RDF graph??
- Can I drop and re-create the DefaultQuadStorage??
- How can I define a graph with virt:rdf_sponger option set to "on"??
- How can I configure Sponger to use Asynchronous Query (AQ) threads??
- How Do I Perform Bulk Loading of RDF Source Files into one or more Graph IRIs?
- How to exploit RDF Schema and OWL Inference Rules with minimal effort??
- How the power of OWL based inference enables us exploit the power of Linked Vocabularies?
- How can I insert binary data to Virtuoso RDF storage in plain queries and with parameter binding via ADO.NET calls??
- How can I replicate all graphs??
- How can I insert RDF data from Visual Studio to Virtuoso??
- How to rename a RDF Graph in the Virtuoso Quad Store??
- How can I configure Virtuoso for maximum performance with available memory??
- How can I use the LOAD command to import RDF data??
- How can I incorporate Content Negotiation into RDF bulk loaders??
- What free-text options can I use with bif:contains??
- How can use bif:contains after SPARUL INSERT??
- How Do I Gecode Data??
- How I Delete a Specific Triple Across Graphs??
- How Do I configure Sponger Cartridges?
- How Do I protect Sponger Endpoint via ACL-s??
- How do I administer Virtuoso Sponger Instance??
- How to control user agent usage of Sponger Resources??
- How Do I use transitive SPARQL query options and Exploit Inference Rules??
- How Do I use Transitivity via Inference Rules and Transitivity for lists??
- How Can I Import Linked Data using the Briefcase "Create" feature??
- What is the ShortenLongURIs Virtuoso configuration parameter??
- How can I fix RDF Quad Store Index corruption in commercial Release 6.2 and earlier builds?
- How Can I perform Simple Linked Data Deployment using Virtuoso's HTTP Re-write Rules??
- How Can I Use Virtuoso's Anytime Query Feature??
- How Can I Split 3.4billion triple UniProt datasets file??
- How Can I insert triples via Digest Authentication into the Quad Store??
- How to Update Large SPARQL Data avoiding database checkpoint abortion??
- How can I Load Data into Virtuoso in Transaction Mode (ie auto commit OFF)??
- How to convert from Row Store to Column Store Table??
- How can I determine the time taken to load datasets with RDF Bulk Loader?
- How to create a RDF Graph Replication slave Subscriber node from a master Publisher node
SPARQL and SPARUL (SPARQL/Update)
- What Virtuoso Sponger SPARQL pragmas are supported??
- Are Custom SPARQL Extension Functions supported and how can I use them??
- How do I configure Virtuoso to support "wide characters" (e.g., Unicode, UTF-8) for SPARQL querying??
- How can I optimize SPARQL query performance using bifs (built-in functions)??
- How can I generate a unique ID via SPARQL??
- What reification alternatives can I use for Linked Data publishing??
- Virtuoso Linked Data Deployment In 3 Simple Steps?
- Is there a difference between a "merge" vs "one by one" execution of queries across named graphs??
- How can I use iSQL to execute SPARQL queries containing the dollar-sign ("$") character??
- How can I set the quad storage to be included in results of queries made to the SPARQL endpoint??
- How can I convert between data types using SPARQL in Virtuoso??
- Is it possible to have the SPARQL endpoint on a different port than the Conductor??
- How can I manage Date Range SPARQL queries??
- How to optimize bif:dateadd in SPARQL query using selective index-friendly filter??
- How do I use SPARUL to change a selection of property values from URI References to Literals??
- How can I use CONSTRUCT with Prepared Statements??
- How can I use Expressions inside CONSTRUCT, INSERT and DELETE?
- How can I use INSERT via CONSTRUCT Statements??
- How can perform SPARUL Updates without transactional log size getting exceed??
- How can I get certificate attributes using SPARQL??
- How does default DESCRIBE mode work??
- How can I dump arbitrary query result as N-Triples??
- How do I bind a named graph parameter in a prepared statement??
- How can I perform Case Insensitive Search across multiple literal values with Virtuoso??
- What is best method to get a random sample of all triples for a subset of all the resources of a SPARQL endpoint??
- How can I use SPARQL to make Meshups??
- How can I get an exact mapping for a date??
- How can I use SPARUL to add missing triples to a Named Graph?
- How can I use the SPARQL IF operator for SPARQL-BI endpoint??
- How can I perform search for predicate values??
- How to clear graphs which are related to empty graphs??
- How can I enable Dynamic Extended Types (DETs) on a Virtuoso SPARQL Endpoint??
- How can I use sub-queries to enable literal values based joins??
- How can I execute query with labels preference order??
- How can I get object datatype??
- How to achieve best performance executing a query against SPARQL Endpoint??
- What methods can I use to protect SPARQL Endpoint??
- How Do I assign SPARQL role to SQL user??
- When should I use the function SAMPLE and when GROUP_CONCAT or GROUP_DIGEST??
- How can I include aggregate function values as objects in SPARQL CONSTRUCT queries??
- How Do I Clean Up Errant Data using SPARQL Update Language??
- How to Use SPARQL to add missing isDefinedBy relations to an Ontology??
- How to Import Ontology??
- How Can I Use MODIFY to update triples??
- What are the supported authentication methods associated with a purpose specific default SPARQL endpoint??
- How Can I execute INSERT/DELETE (SPARUL) statements against a WebID protected SPARQL endpoint??
- How to expose Linked Data View URIs associated with "References" on a given Table??
- How Can I perform SPARQL Date Arithmetic calculations??
- How Can I send SOAP requests to Virtuoso SPARQL Endpoint??
- How Can I manage Custom Controlling Virtuoso Labels for URI functionality??
- How Can I Prevent Limits of Sorted LIMIT/OFFSET query??
- How can I get a full "explain" and "profile" plans for a simple SPARQL query??
- How Can I Use the core feature of SPARQL logic of pattern matching??
- How To Let the SPARQL Endpoint Save Results In WebDAV??
- Where can I find examples for SPARQL 1.1 Features supported in Virtuoso??
- How Can I use Built-In Functions??
- How Can I use BIND??
- How Can I use VALUES??
- How Can I use Sub-queries??
- How Can I use NOT EXISTS and MINUS??
- How Can I use Assignments??
- How Can I use Property Paths??
- How Can I use SPARQL Named Graphs with SPARQL 1.1 Property Paths and Reasoning??
- SPARQL 1.1 Update -- Graph Update:
- SPARQL 1.1 Update -- Graph Management:
- SPARQL 1.1 Graph Store HTTP Protocol:
- How Can I use HTTP POST, HTTP PUT, HTTP GET and HTTP DELETE??
- What SPARQL/SPARUL/SPARQL-BI Operations can I perform within Single/Multiple Statements??
- How Can I use the Virtuoso SPARQL LOAD Service??
- Where can I find examples for SPARQL Arithmetic Functions supported in Virtuoso??
- Where can I find examples for Linked Data SPARQL Reference Using the Gene Ontology??
- How Can I Escape double quotes in entity name??
- How can I use {is property of} syntax to express inverse relations in Turtle??
- How can I use the Virtuoso specific query optimizer hint ASSUME??
- How to discover the capabilities of a SPARQL endpoint en route to enhancing SPARQL-FED usage from Virtuoso instances using LOAD SERVICE ... DATA??
- How to add SPARQL Endpoint Capabilities Interrogation to Virtuoso SPARQL-FED functionality??
- How to discover parameters used by SPARQL services that don't support SPARQL-FED??
- How to handle SPARQL-FED queries for SPARQL endpoints with no OPTION() clause supported??
- How to split a urlencoded ";-" separated list of urls in a SPARQL query?
- How Can I analyze Linked Open Data with R??
- How to Interrogating attributes of a Virtuoso Server instance via SPARQL
Pivot Viewer and CXML
- What are Pivot Collections and does Virtuoso support SPARQL CXML?
- What are the main components of the PivotViewer UI and Collection XML?
- Does the Virtuoso SPARQL protocol endpoint /sparql supports extensions to the SPARQL standard specifically for CXML?
- What RDF to CXML Mapping does Virtuoso support?
- What are the default settings for the CXML generation?
- Where can I find more details about the Auto-Detection of Facet Type?
- Configure the Query Timeout setting for the Virtuoso Facet Browser??
- What are the SparqlCxml Reserved Query Variables?
- How can I use the virtcxml graph?
- How can I use Labels in Place of URIs?
- What are the Link Typing specifics?
- Where can I find examples for SPARQL CXML Queries?
- What are the SparqlCxml Deep Zoom Collections for and how can I use them??
- How can I use the PivotViewer??
- How can I import CXML??
- What is the Facet Pivot Bridge?
- What are DETs and how can I used them for persisting SPARQL Query Results to DAV??
- What CXML params are supported for the SPARQL URL pattern??
- How can I change the Facet "Demo Queries" link??
- How can I change the Facet "/describe" page??
Other areas
- Who Am I?
- How to attach a CSV document to Virtuoso Database Server Instance??
- How to read Virtuoso Transaction logs??
- How can I perform Query Optimization Diagnostics?
- Manage Linked (Open) Data?
- How Can I Use OpenID+WebID??
- How can I use the WebID Identity Provider Proxy Service?
- How can I use the WebID Identity Verification Service?
- How can I use LDAP based WebIDs??
- How can I use the Virtuoso Mail Verification Service??
- How can I enable the Virtuoso Entity Framework 3.5 ADO.Net Provider in Visual Studio 2010??
- How can I write custom crawler using PL??
- How can I make Multi Thread Virtuoso connection using JDBC??
- How can I output the result of a SQL SELECT query from isql to a file in Virtuoso??
- How can I output the results of a SPARQL query run against the /sparql endpoint to a file in Virtuoso??
- How can I setup Server-side Cross-Origin Resource Sharing (CORS) using Virtuoso??
- How can I perform Cross-Origin Resource Sharing (CORS) to enable a Virtuoso SPARQL Endpoint??
- How Can I execute load of sql dump from jdbc??
- How can I make Recording in Virtuoso??
- How can I make internal HTTP redirects??
- Virtuoso Data Center Tips and Tricks?
- Understanding Relationship semantics and reasoning?
- How to Determine Data Usage??
- How to configure the User Agent Identity used by a Virtuoso Sponger instance??
- How to Manage SSL Protocols and Ciphers used with Virtuoso??
- How to extend URIQA DefaultHost value for properly using Facet Browser as search engine??
- Understanding Virtuoso Timezoneless Datetimes