pgsql: Mention tablespaces as a problem for using file system snapshots.

momjian@svr1.postgresql.org (Bruce Momjian) writes:

Mention tablespaces as a problem for using file system snapshots.

This is a considerable disimprovement, since it replaces an example
which is actually relevant to the point with one that isn't necessarily
so. And why did you feel a need to remove the previous example anyway?

regards, tom lane

Tom Lane wrote:

momjian@svr1.postgresql.org (Bruce Momjian) writes:

Mention tablespaces as a problem for using file system snapshots.

This is a considerable disimprovement, since it replaces an example
which is actually relevant to the point with one that isn't necessarily
so. And why did you feel a need to remove the previous example anyway?

The text is now:

If your database is spread across multiple volumes (for example,
if you are using tablespaces) there may not be any way
to obtain exactly-simultaneous frozen snapshots of all the volumes.

I assume many more people are using tablespaces than moving pg_xlog.

You want two examples in that sentence?

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
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Bruce Momjian <pgman@candle.pha.pa.us> writes:

I assume many more people are using tablespaces than moving pg_xlog.

I don't believe that premise. Relocating xlog is an essential step
for high-performance databases ... using tablespaces isn't.

You want two examples in that sentence?

I think the xlog case needs to be mentioned, and I think there needs to
be specific reference to a multi-volume situation. "Using tablespaces"
doesn't necessarily mean the database is spread across multiple disks.

In short, I thought the original wording was better.

regards, tom lane

Tom Lane wrote:

Bruce Momjian <pgman@candle.pha.pa.us> writes:

I assume many more people are using tablespaces than moving pg_xlog.

I don't believe that premise. Relocating xlog is an essential step
for high-performance databases ... using tablespaces isn't.

You want two examples in that sentence?

I think the xlog case needs to be mentioned, and I think there needs to
be specific reference to a multi-volume situation. "Using tablespaces"
doesn't necessarily mean the database is spread across multiple disks.

In short, I thought the original wording was better.

OK, I broke out the examples into a separate sentence. I also update
the rsync mention.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073