pgsql-server: Add: > * Consider using hash buckets to do DISTINCT,

Log Message:
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Add:

* Consider using hash buckets to do DISTINCT, rather than sorting

This would be beneficial when there are few distinct values.

Modified Files:
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pgsql-server/doc:
TODO (r1.1347 -> r1.1348)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/TODO.diff?r1=1.1347&r2=1.1348)