INITIALLOADOPTIONS

Valid For

Oracle GoldenGate 21c (21.8.0) and higher releases for initial load Extract for PostgreSQL.

Description

This parameter is used to enable precision instantiation for an initial load Extract, which allows initial data instantiation without incurring application downtime. The Precise instantiation is achieved by creating a consistent point of the database in relation to the transaction log, or identifiable by a transaction log position like LSN. The initial-load Extract reads the data sets that are already committed up to the consistent point. Changes after that consistent point are not captured by the initial load Extract. A CDC Extract can be used in conjunction to capture the transactions after the precise instantiation LSN.

Queries in snapshot isolation level returns data that are committed by the time the transaction is started. Uncommitted changes after the transaction is started are ignored.

By default, precise instantiation is disabled. To enable precise instantiation, use the INITIALLOADOPTIONS parameter with the USESNAPSHOT option when configuring an online load Extract.

Syntax

INITIALLOADOPTIONS USESNAPSHOT

Examples

The example shows the use of the parameter with the USESNAPSHOT option in the intial load Extract parameter file. The name of the intial load Extract is extinit.

EXTRACT extinit
INITIALLOADOPTIONS USESNAPSHOT
SOURCEDB psql_src USERID ggadmin PASSWORD Welcome 
EXTFILE dirdat/ei, MEGABYTES 500, PURGE
TABLE public.*;

For details on implementation steps, see Add Initial Load Extract for PostgreSQL.