[#10519] fix(postgresql): handle unconstrained NUMERIC type with precision=0

[yuqi1129]

What changes were proposed in this pull request?

In PostgreSqlTypeConverter.toGravitino(), when a PostgreSQL column is defined as NUMERIC without explicit precision/scale, the JDBC driver returns columnSize=0. This was passed directly to Types.DecimalType.of(0, ...) which rejects precision=0 with an IllegalArgumentException.

Fix: map columnSize=null or columnSize=0 to DECIMAL(38, 18) — the maximum supported precision with a sensible default scale.

Why are the changes needed?

Fix: #10519

Unconstrained NUMERIC columns are valid in PostgreSQL and commonly used. Loading any table containing such a column was completely broken.

Does this PR introduce any user-facing change?

Yes — loading tables with unconstrained NUMERIC columns now succeeds, returning DECIMAL(38, 18) instead of throwing an error.

How was this patch tested?

Added unit tests in TestPostgreSqlTypeConverter for both columnSize=0 and columnSize=null cases.

[Copilot]

Pull request overview

This PR fixes PostgreSQL NUMERIC type conversion when the column is declared without explicit precision/scale (unconstrained NUMERIC), which can show up from JDBC metadata as columnSize=0 (or null) and previously caused an IllegalArgumentException in Types.DecimalType.of(...).

Changes:

• Update PostgreSqlTypeConverter.toGravitino() to map unconstrained NUMERIC (columnSize == null || columnSize == 0) to DECIMAL(38, 18) instead of attempting to construct an invalid decimal type.
• Add unit tests to cover both columnSize=0 and columnSize=null cases for NUMERIC.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
catalogs/catalog-jdbc-postgresql/src/main/java/org/apache/gravitino/catalog/postgresql/converter/PostgreSqlTypeConverter.java	Adds guard logic for unconstrained NUMERIC and defaults it to DECIMAL(38, 18) to prevent precision=0 failures.
catalogs/catalog-jdbc-postgresql/src/test/java/org/apache/gravitino/catalog/postgresql/converter/TestPostgreSqlTypeConverter.java	Adds regression coverage for NUMERIC with columnSize=0 and columnSize=null.

[github-actions]

Code Coverage Report

Overall Project	64.86% +0.07%	🟢
Files changed	86.11%	🟢

Module	Coverage
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api	47.14%	🟢
authorization-common	85.96%	🟢
aws	1.1%	🔴
azure	2.6%	🔴
catalog-common	10.0%	🔴
catalog-fileset	80.02%	🟢
catalog-hive	80.98%	🟢
catalog-jdbc-clickhouse	79.06%	🟢
catalog-jdbc-common	42.89%	🟢
catalog-jdbc-doris	80.28%	🟢
catalog-jdbc-hologres	54.03%	🟢
catalog-jdbc-mysql	79.23%	🟢
catalog-jdbc-oceanbase	78.38%	🟢
catalog-jdbc-postgresql	82.35% +2.91%	🟢
catalog-jdbc-starrocks	78.27%	🟢
catalog-kafka	77.01%	🟢
catalog-lakehouse-generic	45.07%	🟢
catalog-lakehouse-hudi	79.1%	🟢
catalog-lakehouse-iceberg	87.15%	🟢
catalog-lakehouse-paimon	77.71%	🟢
catalog-model	77.72%	🟢
cli	44.51%	🟢
client-java	77.83%	🟢
common	49.42%	🟢
core	80.96%	🟢
filesystem-hadoop3	76.97%	🟢
flink	38.86%	🔴
flink-runtime	0.0%	🔴
gcp	14.2%	🔴
hadoop-common	10.39%	🔴
hive-metastore-common	45.82%	🟢
iceberg-common	50.21%	🟢
iceberg-rest-server	66.24% +0.8%	🟢
integration-test-common	0.0%	🔴
jobs	66.17%	🟢
lance-common	23.88%	🔴
lance-rest-server	57.84%	🟢
lineage	53.02%	🟢
optimizer	82.95%	🟢
optimizer-api	21.95%	🔴
server	85.6%	🟢
server-common	69.43%	🟢
spark	32.79%	🔴
spark-common	39.09%	🔴
trino-connector	31.62%	🔴

Files

Module	File	Coverage
catalog-jdbc-postgresql	PostgreSqlTypeConverter.java	98.88%	🟢
iceberg-rest-server	IcebergTableOperations.java	79.14%	🟢