Re: BUG #15609: synchronous_commit=off insert performance regression with secondary indexes

Hi All,

I have found a short term workaround for this. You recreate the index with
an added second column with high-cardinality.
ex. CREATE INDEX ON test_indexes USING BTREE (low_cardinality_column,
primary_key_id);

We have around 1,500 tables with low-cardinality indexes, so its not the
best workaround but one that restores the performance bump for PG11.

Can anyone please shed some light as to why this works?
The only thing I could think of is a locking issue with the leaf nodes.

How much testing is required for this to be considered a proper bug?

Cheers,

Paolo

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