From: Enrico Tassi <enrico.tassi@inria.fr>
Date: Mon, 11 Jul 2005 14:07:04 +0000 (+0000)
Subject: tentative hack for the incredible DB slowdown.
X-Git-Tag: pre_notation~45
X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=commitdiff_plain;h=c1554e961d5147b8fde7c47d783603d77fe4576c;p=helm.git

tentative hack for the incredible DB slowdown.
I suppose we use the DB in a really uncommon way, billions of inserts and
queryes mixed, while (I suppose) the usual is a bunch of inserts and then
billions of queries. ANALYZE TABLE is called sometime to try to ameliorate this
problem.
---

diff --git a/helm/ocaml/metadata/metadataDb.ml b/helm/ocaml/metadata/metadataDb.ml
index 51b432a4f..f18787e83 100644
--- a/helm/ocaml/metadata/metadataDb.ml
+++ b/helm/ocaml/metadata/metadataDb.ml
@@ -138,7 +138,7 @@ let already_indexed _ = false
 let index_constant ~dbd =
   let query = prepare_insert () in
   fun ~uri ~body ~ty  ->
-    if not (already_indexed uri) then begin
+    if not (already_indexed uri) then beginrel_tbl ()
       let name = UriManager.name_of_uri uri in
       let uri = UriManager.string_of_uri uri in
       let metadata = MetadataExtractor.compute ~body ~ty in
@@ -162,8 +162,24 @@ let index_inductive_def ~dbd =
       List.iter (fun (uri, name, _) -> insert_name ~dbd ~uri ~name) metadata
     end
 *)
+
+(***** TENTATIVE HACK FOR THE DB SLOWDOWN - BEGIN *******)
+let analyze_index = ref 0
+let eventually_analyze dbd =
+  incr analyze_index;
+  if !analyze_index > 30 then
+    begin
+      let analyze t = "ANALYZE TABLE " ^ t ^ ";" in
+      List.iter 
+        (fun table -> ignore (Mysql.exec dbd (analyze table)))
+        [name_tbl (); rel_tbl (); sort_tbl (); obj_tbl(); count_tbl()]
+    end
+  
+(***** TENTATIVE HACK FOR THE DB SLOWDOWN - END *******)
+
 let index_obj ~dbd ~uri = 
   if not (already_indexed uri) then begin
+    eventually_analyze dbd;
     let metadata = MetadataExtractor.compute_obj uri in
     let uri_of (a,b,c) = (a,c) in
     let uri = UriManager.string_of_uri uri in