Shulou(Shulou.com)05/31 Report--

In this issue, the editor will bring you about the meaning of add trandata in OGG. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

When configuring OGG, you need to add supplementary logs to the synchronized table, which is executed on the ggsci command line

Add trandata user.table

This command actually has two meanings:

1) if there is competition or UK in table, the destination side can accurately find the data updated by source DML based on competition or UK, so as to synchronize on the destination side.

2) if there is no contention and UK in the table, the destination side can only find the data updated by the source side DML based on all the columns of the table, so as to synchronize on the destination side.

For this OGG command, there is an equivalent syntax in SQL*PLUS:

1) syntax equivalent to the first meaning (with primary key or unique key)

Alter table user.table add?supplemental log group ggs_table_1 (competitive or UK) always

2) syntax equivalent to the second meaning (no primary key and unique key)

Alter table user.table add?supplemental log group ggs_table_1 (all column) always

When the column of a table exceeds 32 fields, an error will be reported by using add trandata:

WARNING OGG-00706 Failed to add supplemental log group on table user.table due to ORA-02257: maximum number of columns exceeded.

At this point, use:

Alter table user.table add?supplemental log... This is the only way.

At this time, there are two situations:

In the first case, there are more than 32 columns, but there are primary or unique keys:

Alter table user.table add?supplemental log group ggs_table_1 (competitive or UK) always

The second case is that there are more than 32 columns, no primary key and unique key:

Alter table user.table add?supplemental log group ggs_table_1 (all column 32) always

The above is what the meaning of add trandata in OGG is shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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