Index Management

インデックスは、テーブルの結合や結果の絞り込みなど、一般的なデータベース操作を高速化するために使用されます。Data VirtualTUALity Serverは、分析ストレージのMaterialized Tableにインデックスを作成し、分析手順をさらに強化します。インデックスがどのように推奨されているか、どのような種類がサポートされているか、その他の質問については、Index Management and Recommended Indexesを参照してください。

SYSADMIN.createIndex

このプロシージャにより、各マテリアライズドテーブルおよびカスタムテーブルにインデックスを作成できます。このためには、データソースが分析ストレージとして設定されているか、importer.defaultSchemaプロパティが設定されている必要があります：

CREATE FOREIGN PROCEDURE createIndex(IN recOptId biginteger, IN columnName string NOT NULL, IN indexType string, IN parentRecOptID biginteger, IN indexKind string, IN tableName string, IN nofail boolean, IN recOptUuid string, IN parentRecOptUuid string, OUT id biginteger NOT NULL RESULT)

Parameters

Parameter	Description
`recOptId`	Specifies `recoptId`, or `recOptUuid`, or `tableName`. If `recoptID` or `recOptUuid` is specified, the system procedure creates an index for the corresponding recommended optimization
`columnName`	Fully qualified column name of the source table, which shall have an index on its materialized table(s)
`indexType`	Type of the index to create. `JOIN`, `WHERE` or `MANUAL` are accepted values. Default: `MANUAL`
`parentRecOptId`	ID of the recommended optimization upon which the materialized table was created
`indexKind`	Current implementation knows only PostgreSQL and Oracle expression-based indexes, so the actual physical expression indexes are only being created for the mentioned DBMS. Possible values: `SINGLE` - single column index (for example: a); `MULTIPLE` - multiple column index (for example: a, b); `EXPRESSION` - expression index (for example: a + b)
`tableName`	Specifies either `recoptId` or `tableName`. If `tableName` is specified, the index is created on the corresponding table in the specified schema
`nofail`	Specifies if the stored procedure should fail or not in case of errors. Default: `FALSE`
`recOptUuid`	Specifies `recoptId`, or `recOptUuid`, or `tableName`. If `recoptID` or `recOptUuid` is specified, the system procedure creates an index for the corresponding recommended optimization
`parentRecOptUuid`	UUID of the recommended optimization upon which the materialized table was created

Example

CALL SYSADMIN.createIndex(1, 'test_tables_pg.test_a.a', 'MANUAL', NULL, 'SINGLE') ;

CREATE TABLE dwh.testIndex (a integer, b integer);;
 
--Single kind:
CALL "SYSADMIN.createIndex"(
 "columnName" => 'a',
 "tableName" => 'dwh.testIndex'
);;
 
--Multiple kind:
CALL "SYSADMIN.createIndex"(
 "columnName" => 'a,b',
 "tableName" => 'dwh.testIndex',
 "indexKind"=> 'MULTIPLE'
);;
 
--Expression kind:
CALL "SYSADMIN.createIndex"(
 "columnName" => 'dwh.testIndex.a + dwh.testIndex.b',
 "tableName" => 'dwh.testIndex',
 "indexKind"=> 'EXPRESSION'
);;

SYSADMIN.dropIndex

SYSADMIN.dropIndex(IN recOptId biginteger, IN columnName string NOT NULL, IN indexType string, IN dropPhysical boolean, IN recOptUuid string)

Parameters

Parameter	Description
`recOptId`	ID of the corresponding recommended optimization. If recoptID is specified, the system procedure drops an index for the corresponding recommended optimization matched with columnName and IndexType
`columnName`	Fully qualified column name of the index to be dropped. Case must match the entry in the `SYSADMIN.RecommendedIndexes` system table
`indexType`	Type of the index to create. `JOIN`, `WHERE` or `MANUAL` are accepted values. If the passed parameter is `NULL`, all the indexes related to the given recommended optimization will be dropped
`dropPhysical`	If set to `TRUE`: physical index will be removed from the most recent materialized table (if any); If set to `FALSE`: index will not be removed from the physical table. Default: `TRUE`
`recOptUuid`	UUID of the corresponding recommended optimization. The system procedure drops an index for the corresponding recommended optimization matched with columnName and IndexType

The recOptId or recOptUuid must be specified.

インデックスを削除する別の方法は、以下のようにインデックスIDまたは名前のみを使用することです。

SYSADMIN.dropIndexById

CREATE FOREIGN PROCEDURE dropIndexById(IN indexId biginteger NOT NULL, IN dropPhysical boolean)

SYSADMIN.dropIndexByName

CREATE FOREIGN PROCEDURE dropIndexByName(IN tableName string NOT NULL, IN indexName string NOT NULL)

Example

CALL SYSADMIN.dropIndexByName(tableName => 'dwh.testindex', indexName => 'testindex_1454927209895');;

ここで、indexNameは DBMS におけるインデックスの名前です。インデックス名は通常、SYS.KeysとSYS.KeyColumnsテーブルに表示されます。

SYSADMIN.importIndex

CREATE FOREIGN PROCEDURE importIndex(IN recOptId biginteger NOT NULL, IN columnName string NOT NULL, IN indexType string, IN parentRecOptID biginteger, IN indexKind string, IN recOptUuid string, IN parentRecOptUuid string, OUT id biginteger NOT NULL RESULT)

Parameters

Parameter	Description
`recOptId`	Specifies `recoptId`, or `recOptUuid`, or `tableName`. If `recoptID` or `recOptUuid` is specified, the system procedure creates an index for the corresponding recommended optimization
`columnName`	Fully qualified column name of the source table having an index on its materialized table(s)
`indexType`	Type of the index to import. `JOIN`, `WHERE` or `MANUAL` are accepted values. Default: MANUAL
`dropPhysical`	If set to `TRUE`: physical index will be removed from the most recent materialized table (if any); If set to `FALSE`: index will not be removed from the physical table. Default: `TRUE`
`parentRecOptId`	ID of the recommended optimization upon which the materialized table was created
`indexKind`	Current implementation knows only PostgreSQL and Oracle expression-based indexes, so the actual physical expression indexes are only being created for the mentioned DBMS. Possible values: `SINGLE` - single column index (for example: a); `MULTIPLE` - multiple column index (for example: a, b); `EXPRESSION` - expression index (for example: a + b)
`recOptUuid`	Specifies `recoptId`, or `recOptUuid`, or `tableName`. If `recoptID` or `recOptUuid` is specified, the system procedure creates an index for the corresponding recommended optimization
`parentRecOptUuid`	UUID of the recommended optimization upon which the materialized table was created

Example

CALL SYSADMIN.importIndex(2, 'test_tables_or.test_a.a,test_tables_or.test_a.b', 'MANUAL', null, 'MULTIPLE') ;
 
CALL SYSADMIN.importIndex(1, 'FLOOR(test_tables_pg.test_a.a)', 'MANUAL', null, 'EXPRESSION') ;