Re: POC: make mxidoff 64 bits
| От | wenhui qiu |
|---|---|
| Тема | Re: POC: make mxidoff 64 bits |
| Дата | |
| Msg-id | CAGjGUA+dcV7veaCV1H65vCNsbS++nT8=ho772gDvsXUW9H7eXQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | POC: make mxidoff 64 bits (Maxim Orlov <orlovmg@gmail.com>) |
| Список | pgsql-hackers |
HI Maxim Orlov
> After a bit of thought, I've realized that to be conservative here is the way to go.
>We can reuse a maximum of existing logic. I mean, we can remove offset wraparound "error logic" and reuse "warning logic". But set the threshold for "warning >logic" to a much higher value. For now, I choose 2^32-1. In other world, legit logic, in my view, here would be to trigger autovacuum if the number of offsets (i.e. >difference nextOffset - oldestOffset) exceeds 2^32-1. PFA patch set.good point ,Couldn't agree with you more. xid64 is the solution to the wraparound problem,The previous error log is no longer meaningful ,But we might want to refine the output waring log a little(For example, checking the underlying reasons why age has been increasing),Though we don't have to worry about xid wraparound
+/*
+ * Multixact members warning threshold.
+ *
+ * If difference bettween nextOffset and oldestOffset exceed this value, we
+ * trigger autovacuum in order to release the disk space if possible.
+ */
+#define MULTIXACT_MEMBER_AUTOVAC_THRESHOLD UINT64CONST(0xFFFFFFFF)
+ * Multixact members warning threshold.
+ *
+ * If difference bettween nextOffset and oldestOffset exceed this value, we
+ * trigger autovacuum in order to release the disk space if possible.
+ */
+#define MULTIXACT_MEMBER_AUTOVAC_THRESHOLD UINT64CONST(0xFFFFFFFF)
Can we refine this annotation a bit? for example
+/*
+ * Multixact members warning threshold.
+ *
+ * If difference bettween nextOffset and oldestOffset exceed this value, we
+ * trigger autovacuum in order to release the disk space ,reduce table bloat if possible.
+ */
+#define MULTIXACT_MEMBER_AUTOVAC_THRESHOLD UINT64CONST(0xFFFFFFFF)
+ * Multixact members warning threshold.
+ *
+ * If difference bettween nextOffset and oldestOffset exceed this value, we
+ * trigger autovacuum in order to release the disk space ,reduce table bloat if possible.
+ */
+#define MULTIXACT_MEMBER_AUTOVAC_THRESHOLD UINT64CONST(0xFFFFFFFF)
Thanks
Maxim Orlov <orlovmg@gmail.com> 于2024年10月23日周三 23:55写道：
After a bit of thought, I've realized that to be conservative here is the way to go.
We can reuse a maximum of existing logic. I mean, we can remove offset wraparound "error logic" and reuse "warning logic". But set the threshold for "warning logic" to a much higher value. For now, I choose 2^32-1. In other world, legit logic, in my view, here would be to trigger autovacuum if the number of offsets (i.e. difference nextOffset - oldestOffset) exceeds 2^32-1. PFA patch set.
--Best regards,Maxim Orlov.
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