On Aug 26, 2011, at 5:23 PM, Andrew Dunstan wrote: > On 08/26/2011 04:46 PM, Jim Nasby wrote: >> On Aug 26, 2011, at 12:15 PM, Andrew Dunstan wrote: >>> I knew there would be some bike-shedding about how we specify these things, >>> which is why I haven't written docs yet. >> While we're debating what shade of yellow to paint the shed... >> >> My actual use case is to be able to be able to "inject" SQL into a >> SQL-formatted dump either pre- or post-data (I'm on 8.3, so I don't actually >> dump any data; I'm *mostly* emulating the ability to dump data on just >> certain tables). >> >> So for what I'm doing, the ideal interface would be a way to tell pg_dump >> "When you're done dumping all table structures but before you get to any >> constraints, please run $COMMAND and inject it's output into the dump >> output." For some of the data obfuscation we're doing it would be easiest if >> $COMMAND was a perl script instead of SQL, but we could probably convert it. >> >> Of course, many other folks actually need the ability to just spit out >> specific portions of the dump; I'm hoping we can come up with something that >> supports both concepts. >> > > Well, the Unix approach is to use tools that do one thing well to build up > more complex tools. Making pg_dump run some external command to inject things > into the stream seems like the wrong thing given this philosophy. Use pg_dump > to get the bits you want (pre-data, post-data) and sandwich them around > whatever else you want.
I agree... except for one little niggling concern: If pg_dump is injecting something, then the DDL is being grabbed with a single, consistent snapshot. --pre and --post do not get you that (though we could probably use the new ability to export snapshots to fix that...) > As for getting data from just certain tables, I just posted a patch for > pg_dump to exclude data for certain tables, and we could look at providing a > positive as well as a negative filter if there is sufficient demand. Unfortunately some of the dumped data needs to be sanitized, so that won't work unless I can also dump an arbitrary SELECT. But yes, a positive filter would definitely be welcome. -- Jim C. Nasby, Database Architect j...@nasby.net 512.569.9461 (cell) http://jim.nasby.net -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
