Re: Compress ReorderBuffer spill files using LZ4

On Thu, Jun 6, 2024 at 4:28 PM Julien Tachoires <julmon@gmail.com> wrote:
>
> When the content of a large transaction (size exceeding
> logical_decoding_work_mem) and its sub-transactions has to be
> reordered during logical decoding, then, all the changes are written
> on disk in temporary files located in pg_replslot/<slot_name>.
> Decoding very large transactions by multiple replication slots can
> lead to disk space saturation and high I/O utilization.
>

Why can't one use 'streaming' option to send changes to the client
once it reaches the configured limit of 'logical_decoding_work_mem'?

>
> 2. Do we want a GUC to switch compression on/off?
>

It depends on the overhead of decoding. Did you try to measure the
decoding overhead of decompression when reading compressed files?

--
With Regards,
Amit Kapila.