BigSerial and txid issuance

["Yorwerth, Adam" <Adam.Yorwerth@xxxxxxxxx>]

Hi Everyone,

 

We’re trying to solve a problem that relies on BigSerial and txid (as returned by txid_current() ) values being issued consistently.

 

Is it possible for two transactions to interleave their issuance of these two variables?

 

For example:

 

Schema:

 

CREATE TABLE EXAMPLE(
  offset bigint PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY NOT NULL,
  txid BIGINT NOT NULL DEFAULT 1
);

 

Insert statement:

 

"INSERT INTO EVENTS (txid) VALUES (txid_current());";

 

 

Prior to transactions executing offset is 10 and txid is 1000.

 

Transaction 1 and 2 occur concurrently.

 

Is it possible for transaction 1 to be issued txid 1001 and offset 12 and transaction 2 to be issued txid 1002 and offset 11?

 

Any help would be much appreciated.

 

Regards,

 

Adam

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