[YSQL] Wrong number of responses error from query using multi-column index with yb_hash_code clause

[timothy-e]

Jira Link: DB-6354

Description

CREATE TABLE t as select x, x as y from generate_series(1, 10) x;
CREATE INDEX t_x_hash_y_asc_idx ON t (x HASH, y ASC);
EXPLAIN ANALYZE SELECT yb_hash_code(x), y FROM t WHERE yb_hash_code(x) = 2675 AND y IN (5, 6);
-- or --
EXPLAIN ANALYZE SELECT yb_hash_code(x), y FROM t WHERE yb_hash_code(x) < 4000 AND y IN (5, 6);

terminates with error

ERROR:  Wrong number of responses: 0, while 1 expected: 0 vs 1
FATAL:  terminating connection due to administrator command

The query does not fail if:

• the y condition is just y = 5
• the x condition is just x = 5 instead of yb_hash_code

This issue could also be used to reproduce a case for to help with #16445, because the session is terminated but the ysqlsh does not disconnect:

yugabyte=# EXPLAIN ANALYZE SELECT yb_hash_code(x), y FROM t WHERE yb_hash_code(x) = 2675 AND y IN (5, 6);
ERROR:  Wrong number of responses: 0, while 1 expected: 0 vs 1
FATAL:  terminating connection due to administrator command
yugabyte=#
yugabyte=# \d
SSL connection has been closed unexpectedly
The connection to the server was lost. Attempting reset: Failed.
!>
!>
!> \d
You are currently not connected to a database.
!> \d
You are currently not connected to a database.
!>

Possibly related to #16761 or #17042 because of similar error messages.

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[fizaaluthra]

JFYI the Wrong number of responses error was a regression that was masking RPC layer errors -- fixed by commit eb6fae3

The unmasked error is:

yugabyte=# EXPLAIN ANALYZE SELECT yb_hash_code(x), y FROM t WHERE yb_hash_code(x) = 2675 AND y IN (5, 6);
ERROR:  recvmsg error: Connection reset by peer

Also, I believe this is a regression because I had to git pull to latest master to repro it locally.

[fizaaluthra]

Regression after commit fc57665 cc @tanujnay112