Re: Improve WALRead() to suck data directly from WAL buffers when possible

On Wed, 2024-01-10 at 19:59 +0530, Bharath Rupireddy wrote:
> I've addressed the above review comments and attached v19 patch-set.

Regarding:

-       if (!WALRead(state, cur_page, targetPagePtr, XLOG_BLCKSZ, tli,
-                                &errinfo))
+       if (!WALRead(state, cur_page, targetPagePtr, count, tli,
&errinfo))

I'd like to understand the reason it was using XLOG_BLCKSZ before. Was
it a performance optimization? Or was it to zero the remainder of the
caller's buffer (readBuf)? Or something else?

If it was to zero the remainder of the caller's buffer, then we should
explicitly make that the caller's responsibility.

Regards,
    Jeff Davis