column_name är inte begränsat till kolumnerna i indexdefinitionen. Alla kolumner i bastabellen kan anges, förutom när du partitionerar ett unikt index , column_name måste väljas bland dem som används som unik nyckel. Med den här begränsningen kan databasmotorn ...
TSqlParserToken TSqlScript TSqlStatement TSqlStatementSnippet TSqlTokenType TSqlTriggerEventGroupHelper TSqlTriggerEventTypeHelper UnaryExpression UnaryExpressionType UniqueConstraintDefinition UniqueRowFilter UnpivotedTableReference UnqualifiedJoin UnqualifiedJoinType UpdateCall UpdateDeleteSpecificatio...
Nonunique nonclustered indexes can be created online when the table has columns using the LOB data types but none of these columns are used in the index definition as either key or included columns. Indexes on local temp ta...
Informix SQL跟踪 热度: Index Index-1 A ANSIcompliance -ansiflag2-4 C Cartesianproduct6-33 CASEexpression1-17 Concatenation8-8 Concurrency7-3 read7-3 update7-3 Crossjoin6-33 D Datamanipulationlanguage definitionof1-3 DELETEstatement1-20 ...
The advantage of disabling an index over dropping an index is that when you disable an index for a table the index definition will remain in metadata and at the same time the index statistics are kept ON for non-clustered indexes.
2 A Sch-M object lock with the resource subtype INDEX_OPERATION prevents the execution of concurrent data definition language (DDL) operations on the source and preexisting structures while the index operation is in progress. For example, this lock prevents concurrent rebuild of two indexes on the...
If index options aren't specified, the existing index option values in sys.indexes are applied. For any index option whose value doesn't appear in sys.indexes, the default indicated in the argument definition of the option applies. If ALL is specified and the underlying table is a heap, ...
SqlParser.SqlCodeDom Microsoft.SqlServer.Management.SqlParser.SqlCodeDom CreateIndexKeyList CreateIndexStart CreateTypeStatementInfo CreateUserStatementFactory CursorDefinitionInfo DdlTargetObjectType DmlTarget FunctionDefinitionFactory FunctionVariableNameAndTableReturnTypePair IDdlTriggerDefinitionInfo IDmlTrigger...
Nonunique nonclustered indexes can be created online when the table has columns using the LOB data types but none of these columns are used in the index definition as either key or included columns. Indexes on local temp tables can't be created, rebuilt, or dropped online. This restriction ...
You can create a multi-valued index in a CREATE TABLE, ALTER TABLE, or CREATE INDEX statement. This requires using CAST(... AS ... ARRAY) in the index definition, which casts same-typed scalar values in a JSON array to an SQL data type array. A virtual column is then generated trans...