Altering a column type - Most efficient way - Mailing list pgsql-performance

From Ow Mun Heng
Subject Altering a column type - Most efficient way
Date
Msg-id 1215676380.15319.2.camel@neuromancer.home.net
Whole thread Raw
Responses Re: Altering a column type - Most efficient way  (Mario Weilguni <mweilguni@sime.com>)
List pgsql-performance
Is there any quick hacks to do this quickly? There's around
20-30million
rows of data.

I want to change a column type from varchar(4) to varchar()

table size is ~10-15GB (and another 10-15G for indexes)

What would be the preferrred way of doing it? SHould I be dropping the
indexes 1st to make things faster? Would it matter?

The punch line is that since the databases are connected via slony, this
makes it even harder to pull it off. My last try got the DDL change
completed in like 3 hours (smallest table of the bunch) and it hung
everything.






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