Re: Fix logical decoding not track transaction duringSNAPBUILD_BUILDING_SNAPSHOT

Hi Haiyang,

Thank you for your summary.

One important thing is that we must not skip any call to ReorderBufferXidSetCatalogChanges() (direct or indirect)
duringfast-forwarding or building snapshot, because the historic snapshot only tracks txns with catalog changes, the
v6-0004seems to skip it in xact_decode(). 

Here is a related bug:

https://www.postgresql.org/message-id/flat/tencent_3A071B760AA1A38540B57F297332B7781C08%40qq.com

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Regards,
ChangAo Chen