/**
* MySQL Resource - sys Schema
*/
import type { MySQLAdapter } from "../MySQLAdapter.js";
import type {
ResourceDefinition,
RequestContext,
} from "../../../types/index.js";
export function createSysSchemaResource(
adapter: MySQLAdapter,
): ResourceDefinition {
return {
uri: "mysql://sysschema",
name: "sys Schema Diagnostics",
title: "MySQL sys Schema Summary",
description: "Key diagnostic information from MySQL sys schema views",
mimeType: "application/json",
annotations: {
audience: ["user", "assistant"],
priority: 0.7,
},
handler: async (_uri: string, _context: RequestContext) => {
try {
// Performance optimization: run all three independent queries in parallel
const [usersResult, statementsResult, locksResult] = await Promise.all([
// Top resource consumers
adapter.executeQuery(`
SELECT user, total_connections, current_connections,
total_memory_allocated as memory_bytes
FROM sys.user_summary
ORDER BY total_memory_allocated DESC
LIMIT 5
`),
// Slow statements
adapter.executeQuery(`
SELECT SUBSTRING(query, 1, 100) as query_preview,
exec_count, total_latency, avg_latency
FROM sys.statements_with_runtimes_in_95th_percentile
LIMIT 5
`),
// Current lock waits
adapter.executeQuery(`
SELECT COUNT(*) as lock_wait_count FROM sys.innodb_lock_waits
`),
]);
const lockRow = locksResult.rows?.[0];
return {
available: true,
topUsers: usersResult.rows ?? [],
slowStatements: statementsResult.rows ?? [],
currentLockWaits: Number(lockRow?.["lock_wait_count"] ?? 0),
};
} catch {
return {
available: false,
message: "sys schema not available or insufficient privileges",
};
}
},
};
}
