Re: Historic snapshot doesn't track txns committed in BUILDING_SNAPSHOT state

Hi,

4, 5 ===

&gt; if (SnapBuildCurrentState(builder) < SNAPBUILD_BUILDING_SNAPSHOT ||
&gt;&nbsp; &nbsp; &nbsp;(SnapBuildCurrentState(builder) == SNAPBUILD_BUILDING_SNAPSHOT &amp;&amp; info != XLOG_HEAP_INPLACE) ||
&gt;&nbsp; &nbsp; &nbsp;ctx-&gt;fast_forward)
&gt;&nbsp; &nbsp; &nbsp;return;

I think during fast forward, we also need handle the xlog that marks a transaction
as&nbsp;catalog modifying, or the snapshot might lose some transactions?

&gt; That way we'd still rely on what's being done in the XLOG_HEAP_INPLACE case

+ if (SnapBuildCurrentState(builder) &gt;= SNAPBUILD_BUILDING_SNAPSHOT)
+ {
+ /* Currently only XLOG_HEAP_INPLACE means a catalog modifying */
+ if (info == XLOG_HEAP_INPLACE &amp;&amp; TransactionIdIsValid(xid))
+ ReorderBufferXidSetCatalogChanges(ctx-&gt;reorder, xid, buf-&gt;origptr);
+ }

We only call&nbsp;ReorderBufferXidSetCatalogChanges() for the xlog that marks a transaction as&nbsp;catalog
modifying, and we don't care about the other steps being done in the xlog, so I think the current
approach is ok.

--
Regards,
ChangAo Chen