Thread: pgsql: Doc: add a bit to indices.sgml about what is an indexable clause

Doc: add a bit to indices.sgml about what is an indexable clause.

We didn't explain this clearly until somewhere deep in the
"Extending SQL" chapter, but really it ought to be mentioned
in the introductory material too.

Discussion: https://postgr.es/m/4097442.1694967650@sss.pgh.pa.us

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/b7412e293b6b3bf9dd02596d6f6be456a0597d58

Modified Files
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doc/src/sgml/indices.sgml | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)