sql - Postgres using the primary key index as a covering index -


i'm wondering if, in postgres, there downsides piggybacking fields index implicitly created primary key in order not have create more indices.

this common technique in creating clustered indices in sql server.

edit

good article on postgres indexing. seems postgres indexing dynamics different sql server.

no not possible.

postgresql cannot "include" columns without making them "active" in index.

currently postgresql not support index scans. included in upcoming 9.2 release though.

but adding columns index don't need might impose performance penalty updates because non-indexed column more efficient update indexed column.


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