HI, On Sep 21, 2022, 11:59 +0800, James Sewell <james.sew...@gmail.com>, wrote: > Hello Hackers! > > Is it possible to get the current virtual txid from C somehow? > > I've looked through the code, but can't seem to find anything other than > getting a NULL when there is no (real) xid assigned. Maybe I'm missing > something? > > Cheers, > James
Virtual xid is meaningful only inside a read-only transaction. It’s made up of MyProc->BackendId and MyProc->LocalTransactionId. To catch it, you can begin a transaction, but don’t exec sqls that could change the db. And gdb on process to see( must exec a read only sql to call StartTransaction, else MyProc->lxid is not assigned). ``` Begin; // do nothing ``` gdb on it and see ``` p MyProc->lxid p MyProc->backendId ``` Regards, Zhang Mingli
