Re: GSoC 2017: weekly progress reports (week 6)

On 1 October 2017 at 01:47, Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru>
wrote:

> On Sat, Sep 30, 2017 at 6:12 PM, Shubham Barai <shubhambaraiss(at)gmail(dot)com>
> wrote:
>
>> I have made changes according to your suggestions. Please have a look at
>> the updated patch.
>> I am also considering your suggestions for my other patches also. But, I
>> will need some time to
>> make changes as I am currently busy doing my master's.
>>
>
> I don't understand why sometimes you call PredicateLockPage() only when
> fast update is off. For example:
>
> @@ -94,6 +101,9 @@ scanPostingTree(Relation index, GinScanEntry scanEntry,
>> break; /* no more pages */
>>
>> buffer = ginStepRight(buffer, index, GIN_SHARE);
>> +
>> + if (!GinGetUseFastUpdate(index))
>> + PredicateLockPage(index, BufferGetBlockNumber(buffer), snapshot);
>> }
>>
>> UnlockReleaseBuffer(buffer);
>
>
> But sometimes you call PredicateLockPage() unconditionally.
>
> @@ -131,6 +141,8 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack
>> *stack,
>> attnum = scanEntry->attnum;
>> attr = btree->ginstate->origTupdesc->attrs[attnum - 1];
>>
>> + PredicateLockPage(btree->index, stack->buffer, snapshot);
>> +
>> for (;;)
>> {
>> Page page;
>
>
> As I understand, all page-level predicate locking should happen only when
> fast update is off.
>
> Also, despite general idea is described in README-SSI, in-code comments
> would be useful.
>
>
Hi Alexander,

Yes, page-level predicate locking should happen only when fast update is
off.
Actually, I forgot to put conditions in updated patch. Does everything else
look ok ?

Kind Regards,
Shubham

>