Re: Online enabling of checksums

Hello

I tried build this patch and got error during make docs
> postgres.sgml:19626: element xref: validity error : IDREF attribute linkend references an unknown ID "runtime-checksumhelper-cost-limit"
> postgres.sgml:19625: element xref: validity error : IDREF attribute linkend references an unknown ID "runtime-checksumhelper-cost-delay"

Both new GUC checksumhelper_cost_delay and checksumhelper_cost_limit mentioned in postgresql.conf with special value -1 (-1 to use vacuum_cost_limit), but this value was not mentioned in docs. I noticed that the code and documentation describe different defaults.
Also i found one "<literal>in progress</literal>" in pg_enable_data_checksums() description. In other places status is called "inprogress" (without space).

> VacuumPageHit = 0;
> VacuumPageMiss = 0;
> VacuumPageDirty = 0;
Hm, why these settings are set to 0 in checksumhelper process?

> /*
> * Force a checkpoint to get everything out to disk. XXX: this should
> * probably not be an IMMEDIATE checkpoint, but leave it there for now for
> * testing
> */
> RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_IMMEDIATE);
We need not forget that.

regards, Sergei