Avoid reading llmeta disableskipscan tunable for all tables during an…

…alyze stat load.

Instead, read at the server start and when that tunable changes for any table (which is signaled by a scdone sc_analyze message).

Signed-off-by: Dorin Hogea <dhogea@bloomberg.net>

db/comdb2.c

@@ -5601,6 +5601,9 @@ int main(int argc, char **argv)
         exit(1);
     }
 
+    /* read disableskipscan here */
+    get_disable_skipscan_all();
+
     /*
       Place a freeze on tunables' registration. This is done to
       avoid multiple re-registration during the creation of temp

db/comdb2.h

@@ -3673,4 +3673,6 @@ void csc2_allow_bools(void);
 void csc2_disallow_bools(void);
 int csc2_used_bools(void);
 
+void get_disable_skipscan_all();
+
 #endif /* !INCLUDED_COMDB2_H */

db/sqlinterfaces.c

@@ -2594,6 +2594,13 @@ static int reload_analyze(struct sqlthdstate *thd, struct sqlclntstate *clnt,
     extern volatile int analyze_running_flag;
     if (analyze_running_flag)
         return 0;
+
+    /* a change in disableskipscan comes on replicant as a sc_analyze scdone log
+     * read here the llmeta entries for that tunable (instead of deep down in
+     * sqlite3AnalysisLoad)
+     */
+    get_disable_skipscan_all();
+
     int rc, got_curtran;
     rc = got_curtran = 0;
     if (!clnt->dbtran.cursor_tran) {

sqlite/src/analyze.c

@@ -145,7 +145,6 @@
 #if defined(SQLITE_BUILDING_FOR_COMDB2)
 #include <logmsg.h>
 int is_comdb2_index_disableskipscan(const char *);
-void get_disable_skipscan_all();
 #endif /* defined(SQLITE_BUILDING_FOR_COMDB2) */
 
 #if defined(SQLITE_ENABLE_STAT4)
@@ -2442,10 +2441,6 @@ int sqlite3AnalysisLoad(sqlite3 *db, int iDb){
   assert( iDb>=0 && iDb<db->nDb );
   assert( db->aDb[iDb].pBt!=0 );
 
-#if defined(SQLITE_BUILDING_FOR_COMDB2)
-  /* AZ: put disabler loader here */
-  get_disable_skipscan_all();
-#endif /* defined(SQLITE_BUILDING_FOR_COMDB2) */
   /* Clear any prior statistics */
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
   for(i=sqliteHashFirst(&pSchema->tblHash); i; i=sqliteHashNext(i)){