#CAPTURE SYNONYM UPDATE#
#CAPTURE SYNONYM DOWNLOAD#

If a column appears in the captured column list that is no longer in the source table, the column is assigned a null value.Ĭhanging the data type of a column in the source table is also recorded in the cdc.ddl_history table. When inserting rows into the change table, the capture process ignores those columns that do not appear in the captured column list associated with the source table.

That is, the definition of the change table remains constant.

These changes are not applied to the change table. Data Definition Language ModificationsĭDL modifications to the source table, such as adding or dropping columns, are recorded in the cdc.ddl_history table. For more information, see Configure the max text repl size Server Configuration Option. To increase this size to support larger LOB data, use the Configure the max text repl size Server Configuration Option to specify a larger maximum size. Computed columns that are included in a capture instance always have a value of NULL.īy default, the maximum size that can be added to a captured column in a single INSERT, UPDATE, WRITETEXT, or UPDATETEXT statement is 65,536 bytes or 64 KB. When _$operation = 1, these columns are assigned their value at the time of the delete. Columns of data type varbinary(max), varchar(max), or nvarchar(max) are assigned a NULL value when _$operation = 3 unless the column changed during the update. Large Object Data TypesĬolumns of data type image, text, and ntext are always assigned a NULL value when _$operation = 1 or _$operation = 3. However, the values in these columns are the same as the source column values. Identity columns are defined as either int or bigint. Timestamp columns are defined as binary(8). Captured Column Data TypesĬaptured columns included in this table have the same data type and value as their corresponding source columns with the following exceptions: For more information, see CDC functionality may break after upgrading to the latest CU for SQL Server 2012, 20.

#CAPTURE SYNONYM DOWNLOAD#

For version and download information, see KB article 3030352 at FIX: The change table is ordered incorrectly for updated rows after you enable change data capture for a Microsoft SQL Server database.

#CAPTURE SYNONYM UPDATE#

The _$command_id column was column was introduced in a cumulative update in versions 2012 through 2016. Tracks the order of operations within a transaction. If no columns were specified in the captured column list, all columns in the source table are included in this table. The remaining columns in the change table are the columns from the source table that were identified as captured columns when the capture instance was created. Can be one of the following:Ĭolumn data has row values before executing the update statement.Ĭolumn data has row values after executing the update statement.Ī bit mask based upon the column ordinals of the change table identifying those columns that changed. Identifies the data manipulation language (DML) operation associated with the change. Sequence value used to order the row changes within a transaction. In SQL Server 2012 (11.x), this column is always NULL. Identified for informational purposes only. For example, if a delete operation on the source table removes two rows, the change table will contain two rows, each with the same _$start_lsn value. Log sequence number (LSN) associated with the commit transaction for the change.Īll changes committed in the same transaction share the same commit LSN. Instead, execute the cdc.fn_cdc_get_all_changes_ and cdc.fn_cdc_get_net_changes_ functions. We recommend that you do not query the system tables directly. For example, if the table Person.Address in the AdventureWorks sample database is enabled for change data capture, the derived change table name would be cdc.Person_Address_CT. capture_instance_CT where capture_instance is the schema name of the source table and the source table name in the format schema_table. When the name of the change table is not specified at the time the source table is enabled, the name is derived. The table returns one row for each insert and delete operation performed against the source table, and two rows for each update operation performed against the source table. Is the change table created when change data capture is enabled on a source table.

Capture synonym