[YSQL] Indexes created on Numeric type are inconsistent

Description

CREATE TABLE test (id SERIAL PRIMARY KEY, c_numeric NUMERIC(12,4));
INSERT INTO test (c_numeric) SELECT (random()*1000)::numeric(12,4) FROM generate_series(1, 10000);
CREATE INDEX test_idx ON test ((c_numeric*2)) ;
select yb_index_check('test_idx'::regclass);

ERROR:  inconsistent index row due to binary mismatch of key attribute
DETAIL:  index: 'test_idx', ybbasectid: '\x4700b3488000059b2121', index attnum: 1

CREATE TABLE test (id SERIAL PRIMARY KEY, c_numeric NUMERIC(12,4));
INSERT INTO test (c_numeric) SELECT (random()*1000)::numeric(12,4) FROM generate_series(1, 10000);
CREATE INDEX test_idx ON test (c_numeric) ;
select yb_index_check('test_idx'::regclass);

Contributor guide

Tech stack

csqlpostgresql

Domain

database

Issue type

bug

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

5

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

over 1 week

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

fresh

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

C programmingDatabase index internalsYugabyteDB codebase structure

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

15

Research direction

Investigate the expression index creation path for NUMERIC type in YugabyteDB. Focus on how the index key is computed and stored, particularly the binary representation of the expression (c numeric*2). Compare with the non expression index case to identify the inconsistency. Examine the yb index check function and related index validation logic. Explore source files handling NUMERIC type serialization and expression evaluation, likely in src/yb/yql/pgsql or src/yb/common directories.