Fix lookup join returning 0 rows when a dimension primary-key component is a literal [fj4WqyCCw3C5ShR1RfB7MoBPTpkRrBFYP1uT35g3MvT]

[waterWang]

Description

When a lookup join condition includes a literal on a dimension table primary key column (e.g. dim_tbl.currency = 'gbp'), Calcite's analyzeCondition() classifies it as a non-equi condition rather than an equi-join key. The LookupJoinOperator builds the lookup key only from leftKeys (equi-join column-column pairs), so the literal component is missing from the key. The key becomes shorter than the dimension table's primary key, causing the lookup to always return null — producing 0 result rows.

Root Cause

The condition dim_tbl.currency = 'gbp' AND dim_tbl.rate_start_date = fact_tbl.rate_start_date is split by Calcite as:

• Equi-join key: dim_tbl.rate_start_date = fact_tbl.rate_start_date → leftKeys/ rightKeys
• Non-equi condition: dim_tbl.currency = 'gbp' (column vs literal)

The operator builds the key from leftKeys only, producing a 1-component key. But the dimension table's primary key is [currency, rate_start_date] (2 components), so the lookup always fails.

Fix

Build the lookup key in the dimension table's primary key column order, filling each position from either:

• The corresponding left column (via equi-join leftKeys/ rightKeys mapping)
• A literal value extracted from non-equi conditions of the form dim_col = literal

Testing

Added lookup_join_literal_key test case to LookupJoin.json with:

• Dim table PK: [currency, rate_start_date]
• Join: dim_tbl.currency = 'gbp' AND dim_tbl.rate_start_date = fact_tbl.rate_start_date
• Expected: 1 result row ['gbp', 125]

Closes #19188