pgsql: Add a few comments about ANALYZE's strategy for collecting MCVs.

Add a few comments about ANALYZE's strategy for collecting MCVs.

Alex Shulgin complained that the underlying strategy wasn't all that
apparent, particularly not the fact that we intentionally have two
code paths depending on whether we think the column has a limited set
of possible values or not.  Try to make it clearer.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/3c69b33f459f62fe6db66c386ef12620ea697f74

Modified Files
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src/backend/commands/analyze.c | 32 ++++++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)