Re: [REVIEW] Re: Compression of full-page-writes

On Fri, Dec 5, 2014 at 11:10 PM, Rahila Syed <rahilasyed(dot)90(at)gmail(dot)com>
wrote:

> I attempted quick review and could not come up with much except this
>
> + /*
> + * Calculate the amount of FPI data in the record. Each backup block
> + * takes up BLCKSZ bytes, minus the "hole" length.
> + *
> + * XXX: We peek into xlogreader's private decoded backup blocks for the
> + * hole_length. It doesn't seem worth it to add an accessor macro for
> + * this.
> + */
> + fpi_len = 0;
> + for (block_id = 0; block_id <= record->max_block_id; block_id++)
> + {
> + if (XLogRecHasCompressedBlockImage(record, block_id))
> + fpi_len += BLCKSZ - record->blocks[block_id].compress_len;
>
>
> IIUC, fpi_len in case of compressed block image should be
>
> fpi_len = record->blocks[block_id].compress_len;
>
Yep, true. Patches need a rebase btw as Heikki fixed a commit related to
the stats of pg_xlogdump.
--
Michael