Modifications to reduce memory consumption. (CVS 2422)

FossilOrigin-Name: 0fd5ce4eefdc429ce0493f15d0dba9e8a3a0b0e2

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.199 2005/03/28 03:39:56 drh Exp $
+** @(#) $Id: pager.c,v 1.200 2005/03/28 08:44:07 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -213,9 +213,16 @@ struct PgHistory {
 
 /*
 ** How big to make the hash table used for locating in-memory pages
-** by page number.
+** by page number. This macro looks a little silly, but is evaluated
+** at compile-time, not run-time (at least for gcc this is true).
 */
-#define N_PG_HASH 2048
+#define N_PG_HASH (\
+  (MAX_PAGES>1024)?2048: \
+  (MAX_PAGES>512)?1024: \
+  (MAX_PAGES>256)?512: \
+  (MAX_PAGES>128)?256: \
+  (MAX_PAGES>64)?128:64 \
+)
 
 /*
 ** Hash a page number