JDBC Connectors

A JDBC connector acts as a bridge across SQL semantic and data type differences between the Data Virtuality Server and a target RDBMS. The Data Virtuality Server has a range of specific connectors that target the most popular open-source and proprietary databases.

On this page, we give general information which is common for all JDBC connectors, and in the subpages, you will find detailed information for each connector.

Connector Configuration

To configure a connection, use the SYSADMIN.createConnection() procedure and specify all required connector properties in the call:

SQL

CALL SYSADMIN.createConnection('somedb', '<type name>', 'db=somedb,user-name=user,password=pwd');
CALL SYSADMIN.createDatasource('somedb', '<type name>', null, null);

Connection, translator, and data source properties for each connector are given in the relevant subpage. Please note that all properties are case-sensitive.

Translator Properties

Translator Properties Shared by All JDBC Connectors

(Properties listed in alphabetical order)

To view the full table, click the expand button in its top right corner

Name	Description	Default value
`comparisonStringConversion`	Sets a template to convert `WHERE` clauses on strings Examples SQL `comparisonStringConversion=%s -- no conversion will be applied comparisonStringConversion=binary %s -- WHERE binary someStringExpression LIKE someOtherStringExpression comparisonStringConversion=(%s COLLATE Latin1_General_CS_AS) -- WHERE (someStringExpression COLLATE Latin1_General_CS_AS LIKE someOtherStringExpression)`	MS SQL Server: `(%s COLLATE Latin1_General_CS_AS)` MySQL, SingleStore: `binary %s` Others: `%s`
`DatabaseTimeZone`	Database time zone, used when fetching date, time, or timestamp values	System default time zone
`DatabaseVersion`	Specific database version, used to fine-tune pushdown support	Automatically detected by the server through the data source JDBC driver, if possible
`forbidNonMatchingNames`	Only considered when `importer.tableNamePattern` is set. When set to `FALSE`, allows creation of tables with names that do not match the `tableNamePattern`. Tables with non-matching names will only be accessible until the server restarts	`TRUE`
`ForceQuotedIdentifiers`	If `TRUE`, all identifiers in the final query (that is being generated by a translator to be sent directly to the target DBMS) will be quoted	`TRUE`
`MaxPreparedInsertBatchSize`	Maximum size of prepared insert batch	`2048`
`OrderByStringConversion`	Sets a template to convert `ORDER BY` clauses on strings Examples SQL `OrderByStringConversion=%s -- no conversion will be applied OrderByStringConversion=(binary %s) -- ORDER BY (binary someStringExpression) OrderByStringConversion=cast((%s) as varchar(2000) ccsid 1208) -- ORDER BY cast((someStringExpression) as varchar(2000) ccsid 1208)`	DB2 for AS/400: `cast((%s) as varchar(2000) ccsid 1208)` DB2 for zOS: `cast((%s) as varchar(2000) ccsid ASCII)` MS SQL Server: `(cast(cast(%s as varchar) as varbinary)` MySQL, SingleStore: (`binary %s)` PostgreSQL: `(%s COLLATE \"C\")` Others: `%s`
`supportsConvertFromClobToString`	If `TRUE`, indicates that the translator supports the `CONVERT`/`CAST` function from `clob` to `string`	MySQL, PostgreSQL, Redshift, Greenplum, Oracle, MS SQL Server: `TRUE` Others: `FALSE`
`supportsNativeQueries`	Forces a translator to issue a `native()` system procedure that can be used to pass native queries directly to an underlying DBMS Example SQL `SELECT x.* FROM table ( CALL "dwh.native"("request" => 'SELECT query, pid, elapsed, substring FROM svl_qlog ORDER BY STARTTIME DESC LIMIT 200') ) w , ARRAYTABLE( w.tuple COLUMNS query string, pid integer , elapsed string, "substring" string ) x;` More usage examples	MySQL, PostgreSQL, Redshift, Snowflake, Oracle, MS SQL Server; Exasol, Vertica, Bigquery, SingleStore, Azure: `TRUE` Others: `FALSE`
`supportsOrderByAlias`	If `FALSE`, the CData Virtuality Server does not generate aliases in the `ORDER BY` clause. If `TRUE`, indicates that the source supports aliases in the `ORDER BY` clause	PostgreSQL: `TRUE` Others: if `OrderByStringConversion` is not set, same as `supportsOrderBy` if `OrderByStringConversion` is set, default for `supportsOrderByAlias` is `FALSE`
`supportsOrderByString`	If `FALSE`, the CData Virtuality Server does not push down the `ORDER BY` clause if it contains at least one expression of `string` type. If `TRUE`, indicates that the source supports strings in the `ORDER BY` clause	MS SQL Server: `FALSE` Others: same as `supportsOrderBy`
`TrimStrings`	If `TRUE`, trims trailing whitespace from fixed-length character strings. Please note that the CData Virtuality Server only has `string` or `varchar` type that treats trailing whitespace as meaningful	`FALSE`
`UseBindVariables`	if `TRUE`, indicates that `PreparedStatements` should be used and that literal values in the source query should be replaced with bind variables. If `FALSE`, only `LOB` values will trigger the use of `PreparedStatements`	`TRUE`
`UseCommentsInSourceQuery`	Embeds a / comment / leading comment with session/request id in the source SQL query for informational purposes	`FALSE`

The names of the translator properties are case-sensitive.

Data Source Properties

Data Source Properties Shared by All JDBC Connectors

(Properties listed in alphabetical order)

To view the full table, click the expand button in its top right corner

Name	Description	Default
`importer.autoCorrectColumnNames`	Replaces `.` in a column name with `_` as the period character is not supported by the CData Virtuality Server in column names	`TRUE`
`importer.catalog`	Database catalogs to use. Can be used if the `db` connection property is omitted. Only for Microsoft SQL Server and Snowflake: Multiple catalogs (multiple databases) usage is supported; `'%'` as a wildcard is allowed: for example, `importer.catalog="foo%"` will import `foo`, `foobar`, etc. To specify several catalog names or/and patterns, values should be comma-separated and enclosed within double quotes: `importer.catalog="schema1,schema2,pattern1%,pattern2%"`; To use all catalogs, the value should be '%': `importer.catalog="%"` To escape a wildcard in a catalog name, use the '\' escape character. The value should be as follows: `importer.catalog="test\_tables"`	Exasol: SQL `EXA_DB` All others: empty
`importer.defaultSchema`	Only for data sources that are also supported as Analytical Storage (SQLServer, MySQL, Oracle, PostgreSQL, Redshift); When the property is correctly set, `SELECT INTO`, `CREATE`, and `DROP TABLE` commands are enabled for that data source; Must point to the original schema name in the DBMS (e.g. `importer.defaultSchema=public`); Needs specifying where tables will be created or dropped in the source DBMS; Not meant to be used with Analytical Storage data source Please note that writing into a data source is only possible if this parameter is set.	Empty
`importer.enableMetadataCache`	Turns on metadata cache for a single data source even when the global option is turned off. Together with `importer.skipMetadataLoadOnStartup=true`, it allows using materialized views after server restart when the original source is unavailable	`FALSE`
`importer.excludeProcedures`	Case-insensitive regular expression that will exclude a matching fully qualified procedure name from import	Empty
`importer.excludeSchemas`	Comma-separated list of schemas (no `%` or `?` wildcards allowed) to exclude listed schemas from import. A schema specified in `defaultSchema` or `schemaPattern` will be imported despite being listed in `excludeSchemas`. Helps to speed up metadata loading	Oracle: SQL `APEX_PUBLIC_USER, DIP, FLOWS_040100, FLOWS_020100, FLOWS_FILES, MDDATA, ORACLE_OCM, SPATIAL_CSW_ADMIN_USR, SPATIAL_WFS_ADMIN_USR, XS$NULL, BI, HR, OE, PM, IX, SH, SYS, SYSTEM, MDSYS, CTXSYS` All others: empty
`importer.excludeTables`	Case-insensitive regular expression that will exclude a matching fully qualified table name from import. Does not speed up metadata loading. Here are some examples: 1. Excluding all tables in the (source) schemas `sys` and `INFORMATION_SCHEMA`: SQL `importer.excludeTables=(.[.]sys[.].\|.[.]INFORMATION_SCHEMA[.].)` 2. Excluding all tables except the ones starting with "public.br" and "public.mk" using a negative lookahead: SQL `importer.excludeTables=(?!public\.(br\|mk)).` 3. Excluding "tablename11" from the list ["tablename1", "tablename11", "company", "companies"]: SQL `importer.excludeTables=.\.(?!\btablename1\b\|\bcompan).` ".\." will match the schema portion of the table name; "\b" is a word boundary. It is used to define the boundary between text characters and non-character text; "\btablename1\b" will only match tablename1 and not tablename11 because of the use of "\b"; "\bcompan" will match "company" and "companies" because we did not use "\b" at the end to delimit a word boundary; ".*" at the end is necessary to match the trailing characters after the name	Empty
`importer.fetchSize`	Fetch size assigned to a resultset on loading metadata	No default value
`importer.importApproximateIndexes`	If set to `TRUE`, imports approximate index information	`TRUE`
`importer.importIndexes`	If set to `TRUE`, imports index/unique key/cardinality information	`FALSE`
`importer.importKeys`	If set to `TRUE`, imports primary and foreign keys	`FALSE`
`importer.importProcedures`	If set to `TRUE`, imports procedures and procedure columns. Overloaded procedures can be imported with an additional option `useProcedureSpecificName`. Please note that it is currently not possible to import procedures which use the same name for more than one parameter (e.g. same name for `IN` and `OUT` parameters). Such procedures can be excluded from import with the parameter `excludeProcedures`. Please note that it is not always possible to import procedure result set columns due to database limitations	`FALSE` `TRUE` only for CData connector
`importer.loadColumnsTableByTable`	Set to `TRUE` to force table by table metadata processing	`FALSE`/`TRUE` only for Netsuite and SAP Advantage Database Server
`importer.loadMetadataWithJdbc`	If set to `TRUE`, turns off all custom metadata load ways	`FALSE`
`importer.loadSourceSystemFunctions`	If set to `TRUE`, data source-specific functions are loaded. Supported for Microsoft SQL Server and Azure	`FALSE`
`importer.procedureNamePattern`	Procedure(s) to import. If omitted, all procedures will be imported. `%` as a wildcard is allowed: for example, `importer.procedureNamePattern=foo%` will import `foo` , `foobar`, etc. W orks only in combination with `importProcedures`	Empty
`importer.quoteNameInSource`	If set to `FALSE`, directs the Data Virtuality Server to create source queries using unquoted identifiers	`TRUE`
`importer.renameDuplicateColumns`	If set to `TRUE`, renames duplicate columns caused by either mixed case collisions or `autoCorrectColumnNames` replacing `.` with `_`. The suffix `_n` where `n` is an integer will be added to make the name unique	`TRUE`
`importer.renameDuplicateTables`	If set to `TRUE`, renames duplicate tables caused by mixed case collisions. The suffix `_n` where `n` is an integer will be added to make the name unique	`TRUE`
`importer.replaceSpecSymbsInColNames`	If set to `TRUE`, replaces all special symbols (any symbols not in the `^A-Za-z0-9_` sequence) to the `_` symbol in column names of tables	`FALSE` / `TRUE` only for BigQuery
`importer.schemaPattern`	Schema(s) to import. If omitted or has "" value, all schemas will be imported. `%` as wildcard is allowed: for example, `importer.schemaPattern=foo%` will import `foo`, `foobar`, etc. To specify several schema names or/and patterns, values should be comma-separated and enclosed within double quotes: `importer.schemaPattern="schema1,schema2,pattern1%,pattern2%"`. For proper escaping of special characters depending on the type of data source, check Escaping special characters in schema names or use wildcards instead: `"[schema_name]"` can be rewritten as `"%schema%name%"`. Helps to speed up metadata loading	Empty
`importer.skipMetadataLoadOnStartup`	If set to `TRUE`, allows skipping metadata loading on server startup if there's cached metadata for the data source. . Together with `importer.enableMetadataCache=true`, it allows using materialized views after server restart when the original source is unavailable	`FALSE`
`importer.tableNamePattern`	Table(s) to import. If omitted, all tables will be imported. `%` as a wildcard is allowed: for example, `importer.tableNamePattern=foo%` will import `foo`, `foobar`, etc	Empty
`importer.tableTypes`	Comma-separated list (without spaces) of table types to import. Available types depend on the DBMS. Usual format: `"TABLE,VIEW"`. Other typical types are `"SYSTEM TABLE"`, `"GLOBAL TEMPORARY"`, `"LOCAL TEMPORARY"`, `"ALIAS"`, `"SYNONYM"`	Empty
`importer.useCatalogName`	If set to `TRUE`, uses any non-null/non-empty catalogue name as part of the name in source, e.g. `"catalogue"."table"."column"`, and in the CData Virtuality Server runtime name if `useFullSchemaName` is `TRUE`. If set to `FALSE`, will not use the catalogue name in either the name in source or the CData Virtuality Server runtime name. Should be set to `FALSE` for sources that do not fully support a catalogue concept, but return a non-null catalogue name in their metadata - such as HSQL	`TRUE` / `FALSE` only for Hive and EXASOL
`importer.useFullSchemaName`	If set to `FALSE`, directs the importer to drop the source catalogue/schema from the CData Virtuality Server object name so that the CData Virtuality Server fully qualified name will be in the form of `<model name>.<table name>`. Please note that this may lead to objects with duplicate names when importing from multiple schemas, which results in an exception	`TRUE`
`importer.useProcedureSpecificName`	If set to `TRUE`, allows the import of overloaded procedures (which will normally result in a duplicate procedure error) by using the unique procedure specific name in the CData Virtuality Server. This option will only work with JDBC 4.0 compatible drivers that report specific names	`FALSE`
`importer.widenUnsignedTypes`	If set to `TRUE`, converts unsigned types to the next widest type. For example, SQL Server reports tinyint as an unsigned type. With this option enabled, tinyint would be imported as a short instead of a byte	`TRUE`

The names of the data source properties are case-sensitive.

Escaping wildcards in importer.catalog available since v4.0.8

Default values importer.catalog='EXA_DB' and importer.useCatalogName=FALSE available since v4.4

importer.loadSourceSystemFunctions is available since v4.6

importer.importProcedures set to TRUE by default for CData connector since v4.7

Data Source Properties Specific for Some Connectors

(Properties listed in alphabetical order)

To view the full table, click the expand button in its top right corner

Name	Description	Default	Connector
`importer.loadAllOracleColumnComments`	Set to `FALSE` to prevent importing column comments during data source creation	`TRUE`	Oracle Database
`importer.loadAllOracleTableComments`	Set to `FALSE` to prevent importing table comments during data source creation	`TRUE`	Oracle Database
`importer.trimColumnNames`	For Hive 0.11.0 and later, metadata for the `DESCRIBE` command could be inappropriately returned with padding. Set to `TRUE` to trim white spaces from column names	`FALSE`	Hive
`importer.useDatabaseMetadata`	For Hive 0.13.0 and later, the normal JDBC DatabaseMetaData facilities are sufficient to perform an import. Set to `TRUE` to use the normal JDBC import logic. Set to `FALSE` to use native Hive methods to import metadata. When `TRUE`, `trimColumnNames` has no effect	`FALSE`	Hive

Escaping Special Characters in Schema Names

Characters that are forbidden for Oracle schema names and can't be escaped: ", /, &, {, }.

All other special characters can be used as they are or should be escaped depending on the type of data source:

"	forbidden	\"	\"	\"
\	\\\\	\\\\\\	\\\\\\	\\\\\\
_	/_	\\\\_	\\\\_	\\\\_
,	\\,	\\,	\\,	\\,
%	/%	\\\\%	\\\\%	\\\\%
[	[	[	[[]	[
'	''	''	''	''''

Usage

With the Data Virtuality Server SQL, the source can be queried as if the tables and procedures were local to the Data Virtuality Server system.