[YSQL] [Transactional DDL] [Colocated Database] Select * OR select count(*) of a table fails with "schema version mismatch" after txn commit

[hariharasudhan-yb]

Jira Link: DB-20252

Description

Version - 2.29.0.0-b511

Encountering an issue where SELECT * or SELECT COUNT(*)  query fails with a schema version mismatch  after committing a transaction. This occurs in a new Txn DDL test where we execute a large number of DDLs (300+ random DDLs) inside a single transaction. The issue is reproducible almost consistently.
It only happens in a colocated database and is not observed in a non-colocated database. Version 2.29.0.0-b511

2026-02-18 13:20:14.825 UTC [25014] STATEMENT:  SELECT * FROM tab_huge_txn_db_7f3f7181 ORDER BY 1;
2026-02-18 13:20:14.825 UTC [25014] ERROR:  schema version mismatch for table 000040000000300080000000000042e7: expected 12, got 11

We are not running any concurrent transactions - all transactions are strictly serial hence it is unexpected. BTW Savepoints are not enabled only object lock and Txn DDL

Logs and Slack details in jira

Issue Type

kind/bug

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