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Work with memory-optimized system-versioned temporal tables

  • Artikkeli

Applies to: SQL Server 2016 (13.x) and later Azure SQL Database Azure SQL Managed Instance

This article discusses how working with a memory-optimized system-versioned temporal table is different from working with a disk-based system-versioned temporal table.

Note

Memory-optimized temporal tables are only available in SQL Server, and not Azure SQL Database.

Discover metadata

To discover metadata about a memory-optimized system-versioned temporal table, you need to combine information from sys.tables and sys.internal_tables. A system-versioned temporal table is presented as parent_object_id of the internal in-memory history table

This example shows how to query and join these tables.

SELECT SCHEMA_NAME(T1.schema_id) AS TemporalTableSchema,
    OBJECT_NAME(IT.parent_object_id) AS TemporalTableName,
    T1.object_id AS TemporalTableObjectId,
    IT.Name AS InternalHistoryStagingName,
    SCHEMA_NAME(T2.schema_id) AS HistoryTableSchema,
    OBJECT_NAME(T1.history_table_id) AS HistoryTableName
FROM sys.internal_tables IT
INNER JOIN sys.tables T1
    ON IT.parent_object_id = T1.object_id
INNER JOIN sys.tables T2
    ON T1.history_table_id = T2.object_id
WHERE T1.is_memory_optimized = 1
    AND T1.temporal_type = 2;

Modify data

Memory-optimized temporal tables can be modified through natively compiled stored procedures, which enable you to convert non-temporal memory-optimized tables, and keep existing natively stored procedures.

This example how previously created table can be modified in natively compiled module.

CREATE PROCEDURE dbo.UpdateFXCurrencyPair (
    @ProviderID INT,
    @CurrencyID1 INT,
    @CurrencyID2 INT,
    @BidRate DECIMAL(8, 4),
    @AskRate DECIMAL(8, 4)
)
WITH NATIVE_COMPILATION, SCHEMABINDING,
EXECUTE AS OWNER
AS
BEGIN ATOMIC
   WITH (
      TRANSACTION ISOLATION LEVEL = SNAPSHOT,
      LANGUAGE = N'English'
   )
   UPDATE dbo.FXCurrencyPairs
   SET AskRate = @AskRate,
      BidRate = @BidRate
   WHERE ProviderID = @ProviderID
      AND CurrencyID1 = @CurrencyID1
      AND CurrencyID2 = @CurrencyID2
END
GO;

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