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fix(kingbase): optimize large query pagination

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This commit is contained in:
zipg
2026-07-20 18:12:54 +08:00
committed by GitHub
parent a9e5af3535
commit 378674253c
1 changed files with 51 additions and 1 deletions
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crates/dbx-core/src/query_result_sql.rs
+51 -1
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@@ -136,7 +136,9 @@ pub fn build_query_pagination_execution_plan(
return plan;
}
if options.use_agent_cursor && options.pagination.offset == 0 {
let can_use_first_page_cursor = options.use_agent_cursor && options.pagination.offset == 0;
let prefer_server_pagination = options.database_type == Some(DatabaseType::Kingbase);
if can_use_first_page_cursor && !prefer_server_pagination {
if !options.first_page_uses_actual_sql {
plan.sql_to_execute = options.query_base_sql;
}
@@ -157,6 +159,17 @@ pub fn build_query_pagination_execution_plan(
plan.page_sql = paginated.sql;
plan.page_limit = Some(options.pagination.limit);
plan.page_offset = Some(options.pagination.offset);
} else if can_use_first_page_cursor {
// Kingbase JDBC may buffer an entire result in auto-commit mode, so use
// LIMIT/OFFSET whenever the statement can be rewritten safely. Keep the
// Agent cursor as a bounded fallback for multi-statement or dialect-
// specific SQL that the pagination parser cannot transform.
if !options.first_page_uses_actual_sql {
plan.sql_to_execute = options.query_base_sql;
}
plan.page_limit = Some(options.pagination.limit);
plan.page_offset = Some(options.pagination.offset);
plan.use_agent_result_session = true;
}
plan
}
@@ -2278,6 +2291,43 @@ WHERE u.id = picked.id;
assert!(plan.use_agent_result_session);
}
#[test]
fn kingbase_prefers_server_pagination_over_agent_cursor() {
let plan = build_query_pagination_execution_plan(QueryPaginationExecutionPlanOptions {
sql: "SELECT * FROM events".to_string(),
query_base_sql: "SELECT * FROM events".to_string(),
database_type: Some(DatabaseType::Kingbase),
pagination: QueryPagination { limit: 500, offset: 0, session_id: None },
use_agent_cursor: true,
first_page_uses_actual_sql: false,
});
assert_eq!(plan.sql_to_execute, "SELECT * FROM events LIMIT 500;");
assert_eq!(plan.page_sql, Some(plan.sql_to_execute.clone()));
assert_eq!(plan.page_limit, Some(500));
assert_eq!(plan.page_offset, Some(0));
assert!(!plan.use_agent_result_session);
}
#[test]
fn kingbase_falls_back_to_agent_cursor_for_unrewritable_queries() {
let sql = "SELECT * FROM events; SELECT 1";
let plan = build_query_pagination_execution_plan(QueryPaginationExecutionPlanOptions {
sql: sql.to_string(),
query_base_sql: sql.to_string(),
database_type: Some(DatabaseType::Kingbase),
pagination: QueryPagination { limit: 500, offset: 0, session_id: None },
use_agent_cursor: true,
first_page_uses_actual_sql: false,
});
assert_eq!(plan.sql_to_execute, sql);
assert!(plan.page_sql.is_none());
assert_eq!(plan.page_limit, Some(500));
assert_eq!(plan.page_offset, Some(0));
assert!(plan.use_agent_result_session);
}
#[test]
fn export_agent_cursor_first_page_keeps_actual_sorted_sql() {
let plan = build_query_pagination_execution_plan(QueryPaginationExecutionPlanOptions {