Re: How to generate specific WAL records?

Koichi Suzuki escribió:
> Hi,
>
> Does anyone know how to generate the following WAL records from psql?
>
> I'm now fixing pg_lesslog, which I reported a bug. Now code is
> almost okay and I'd like to add test tools to show pg_lesslog can
> handle all the WAL record correctly.
>
> XLOG_MULTIXACT_ZERO_OFF_PAGE
> XLOG_MULTIXACT_ZERO_MEM_PAGE
> XLOG_MULTIXACT_CREATE_ID

For these, you need to do SELECT FOR SHARE of a tuple in more than one
concurrent session.

I think HEAP_LOCK is SELECT FOR UPDATE.

> XLOG_BTREE_DELETE_PAGE
> XLOG_BTREE_DELETE_PAGE_META
> XLOG_BTREE_DELETE_PAGE_HALF

These are caused during vacuum of a btree. Create an index, populate
it, then remove all items. Then vacuum twice.

--
Alvaro Herrera http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support