feat: export index usage statistics (#9)

Author: jonstjohn

pkg/export/exporter.go

@@ -158,7 +158,8 @@ var exportTables = []Table{
 			` ROUND((metrics->>'sys.totalmem')::FLOAT / 1073741824, 1) AS total_mem_gib` +
 			` FROM crdb_internal.kv_node_status`,
 	},
-	{Database: "", Name: "crdb_internal.table_indexes", TimeColumn: "", Scope: TenantScopeMain}, // Use "" to query across all databases
+	{Database: "", Name: "crdb_internal.table_indexes", TimeColumn: "", Scope: TenantScopeMain},           // Use "" to query across all databases
+	{Database: "", Name: "crdb_internal.index_usage_statistics", TimeColumn: "", Scope: TenantScopeMain}, // Use "" to query across all databases
 	{Database: "system", Name: "table_statistics", TimeColumn: "", Scope: TenantScopeMain},
 	{
 		Database:        "crdb_internal",

pkg/export/exporter_test.go

@@ -195,6 +195,24 @@ func TestExportTables(t *testing.T) {
 	}
 }
 
+func TestExportTablesIncludesIndexUsageStatistics(t *testing.T) {
+	found := false
+	for _, table := range exportTables {
+		if table.Database == "" && table.Name == "crdb_internal.index_usage_statistics" {
+			found = true
+			if table.Scope != TenantScopeMain {
+				t.Errorf("crdb_internal.index_usage_statistics should have Scope TenantScopeMain, got %q", table.Scope)
+			}
+			if table.TimeColumn != "" {
+				t.Errorf("crdb_internal.index_usage_statistics should have no TimeColumn, got %q", table.TimeColumn)
+			}
+		}
+	}
+	if !found {
+		t.Error("exportTables should contain crdb_internal.index_usage_statistics")
+	}
+}
+
 func TestExportTablesIncludesNodeCPUMem(t *testing.T) {
 	found := false
 	for _, table := range exportTables {