Hi Tom, Thank you for your prompt response. I've run analyze(not vacuum analyze), but it doesn't seem to work. Is there any other way to optimize the database?
At 2022-10-10 00:02:09, "Tom Lane" <t...@sss.pgh.pa.us> wrote: >gzh <gzhco...@126.com> writes: >> I run following sql in PostgreSQL 8.4 and PostgreSQL 12.11, it returns >> different execution plan. > >Have you done an ANALYZE in the new database? The rowcount estimates >seem a lot different, leading me to guess that the newer installation >doesn't have good statistics yet. > > regards, tom lane
