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perf(catalog): ERD neighbourhood and MCP describe/sample read the whole schema catalog; filter tables in SQL

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Evaluación

Dificultad
4/5
Tiempo estimado
3-5 días
Aptitud para principiantes
42/100
Tipo de issue
Error
Claridad
Bien especificado
Estado de actividad
Activo
Stack tecnológico
dart, mysql, postgresql, sqlite
Área
databases, performance

Línea de trabajo

Start with lib/core/erd/erd_catalog.dart:198-248 and lib/core/mcp/mcp_query_service.dart:245-270, then inspect the columnsSql and viewColumnsSql definitions for PostgreSQL, MySQL, and SQLite. Trace how ERD neighbourhood names and MCP table validation flow into those queries, and review the related tests. Done means SQL filters catalog reads to the requested tables, MCP uses a cheap existence check where appropriate, and a neighbourhood remains complete beyond the catalog row limit.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

backend core P3 performance

Problem

Two paths read the whole schema catalog when they need a few tables:

  1. ERD neighbourhood (ErdCatalog.loadNeighbourhood, lib/core/erd/erd_catalog.dart:198-248). It loads all FKs (needed for the graph walk), then for every schema in the neighbourhood runs columnsSql for all columns of that schema and filters in Dart (if (names.contains(r[0])), :230/:238). The PostgreSQL columnsSql has per-column correlated subqueries (unique-index EXISTS, pg_enum string_agg, col_description, pg_get_expr), so the cost grows with the schema, not with the diagram. With catalogRowLimit = 200000 (:19) a large schema is truncated before filtering, so the focused table can lose its columns even though it needs only a few rows.
  2. MCP describe_table / sample_rows (McpQueryService._loadCatalog, lib/core/mcp/mcp_query_service.dart:245-270). To find one table it runs three catalog queries over the whole schema (columns, FKs, view columns) on every call. sample_rows uses the result only to validate the table name.

Fix

  • Add a table filter to columnsSql / viewColumnsSql: PostgreSQL c.relname = ANY($names) per schema, MySQL table_name IN (...), SQLite m.name IN (...) (literal-escaped as in _lit, or bind parameters where the delegate supports them).
  • ERD neighbourhood: walk FKs first, then fetch columns only for the resulting names.
  • MCP: validate the name with a cheap existence query (to_regclass / information_schema.tables / sqlite_master), and describe one table with the filtered column/FK queries. Keep the full catalog only for list_tables and the schema:// resource.
  • Tests: the generated SQL contains the filter; the neighbourhood of a table in a schema larger than the row limit is complete.

Related: ERD epic #1166 and #1167 (same catalog SQL).

Lenguaje dominante
Dart
Estrellas
23
Forks
1
Merge medio
31 min
PR fusionados (30 d)
570

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