Bug Report: Flyway query on information schema not working in OLAP mode

[Anders-PlanetScale]

Overview of the Issue

At PlanetScale we have a customer who uses Flyway to run schema migrations, and has some long-running migrations that are being killed by the query timeout. The customer is setting workload=olap to bypass the query timeouts, but some of the schema introspection queries performed by Flyway are failing.

For example, given a keyspace src, the following query fails in OLTP:

mysql> SET workload=olap; SELECT * FROM information_schema.schemata WHERE schema_name = 'src'\G
Query OK, 0 rows affected (0.00 sec)

ERROR 1105 (HY000): target: src.0.primary: vttablet: rpc error: code = InvalidArgument desc = missing bind var __vtschemaname (CallerID: userData1)

Compare this failure to an OLTP workload query.

mysql> SELECT * FROM information_schema.schemata WHERE schema_name = 'src'\G
*************************** 1. row ***************************
              CATALOG_NAME: def
               SCHEMA_NAME: vt_src
DEFAULT_CHARACTER_SET_NAME: utf8
    DEFAULT_COLLATION_NAME: utf8_general_ci
                  SQL_PATH: NULL
1 row in set (0.01 sec)

Note how the underlying schema name is vt_src. VTTablet is re-writing these queries in OLTP workloads, but not in OLAP (streaming) workloads.

Reproduction Steps

Steps to reproduce this issue:

1. Set up vitess, for testing I used vttestserver:

    docker run -p 3306:33577 \
       -e PORT=33574 -e KEYSPACES="src" -e NUM_SHARDS="1" -e MYSQL_BIND_HOST=0.0.0.0 \
       vitess/vttestserver:mysql80
   

2. Once Vitess is running connect to VTGate.

3. Confirm query works without OLAP:

   mysql> SELECT * FROM information_schema.schemata WHERE schema_name = 'src'\G
   *************************** 1. row ***************************
                 CATALOG_NAME: def
                  SCHEMA_NAME: vt_src
   DEFAULT_CHARACTER_SET_NAME: utf8
       DEFAULT_COLLATION_NAME: utf8_general_ci
                     SQL_PATH: NULL
   1 row in set (0.01 sec)
   

4. Next SET workload=olap and re-run query to see it failing:

   mysql> SET workload=olap; SELECT * FROM information_schema.schemata WHERE schema_name = 'src'\G
   Query OK, 0 rows affected (0.00 sec)
   
   ERROR 1105 (HY000): target: src.0.primary: vttablet: rpc error: code = InvalidArgument desc = missing bind var __vtschemaname (CallerID: userData1)
   

Binary Version

Version: 15.0.0-SNAPSHOT (Git revision d1e7777c1e54fc20347e61df32617657e1199119 branch 'main') built on Tue Aug 23 12:29:35 UTC 2022 by vitess@buildkitsandbox using go1.18.4 linux/amd64

Operating System and Environment details

Debian GNU/Linux 10 (buster)
Linux 5.11.0-7620-generic
x86_64

Log Fragments

No response