Re: Inserting 8MB bytea: just 25% of disk perf used? - Mailing list pgsql-performance

* Matthew Wakeling:

> The data needs to be written first to the WAL, in order to provide
> crash-safety. So you're actually writing 1600MB, not 800.

In addition to that, PostgreSQL 8.4.2 seems pre-fill TOAST files (or
all relations?) with zeros when they are written first, which adds
another 400 to 800 MB.

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