Index: configure.in
===================================================================
--- configure.in	(revision 128)
+++ configure.in	(working copy)
@@ -620,7 +620,8 @@
     strnicmp \
     strstr \
     tzset \
-    uname)
+    uname \
+    getpagesize )
 
 dnl windows has different names for a few basic things
 if test "x-$ac_cv_func_getpid" != "x-yes" -a "x-$ac_cv_func__getpid" = "x-yes" ; then
Index: sm/storage_pgsql.c
===================================================================
--- sm/storage_pgsql.c	(revision 135)
+++ sm/storage_pgsql.c	(revision 136)
@@ -42,15 +42,27 @@
     int txn;
 } *drvdata_t;
 
-#define BLOCKSIZE (1024)
+#define FALLBACK_BLOCKSIZE (4096)
 
 /** internal: do and return the math and ensure it gets realloc'd */
-static int _st_pgsql_realloc(void **oblocks, int len) {
+static size_t _st_pgsql_realloc(void **oblocks, size_t len) {
     void *nblocks;
-    int nlen;
+    size_t nlen;
+    static size_t block_size = 0;
 
+    if (block_size == 0) {
+#ifdef HAVE_GETPAGESIZE
+        block_size = getpagesize();
+#elif defined(_SC_PAGESIZE)
+        block_size = sysconf(_SC_PAGESIZE);
+#elif defined(_SC_PAGE_SIZE)
+        block_size = sysconf(_SC_PAGE_SIZE);    
+#else
+        block_size = FALLBACK_BLOCKSIZE;
+#endif
+    }
     /* round up to standard block sizes */
-    nlen = (((len-1)/BLOCKSIZE)+1)*BLOCKSIZE;
+    nlen = (((len-1)/block_size)+1)*block_size;
 
     /* keep trying till we get it */
     while((nblocks = realloc(*oblocks, nlen)) == NULL) sleep(1);
Index: sm/storage_pgsql.c
===================================================================
--- sm/storage_pgsql.c	(revision 138)
+++ sm/storage_pgsql.c	(revision 139)
@@ -71,7 +71,7 @@
 }
 
 /** this is the safety check used to make sure there's always enough mem */
-#define PGSQL_SAFE(blocks, size, len) if((size) > len) len = _st_pgsql_realloc((void**)&(blocks),(size));
+#define PGSQL_SAFE(blocks, size, len) if((size) >= len) len = _st_pgsql_realloc((void**)&(blocks),(size + 1));
 
 static void _st_pgsql_convert_filter_recursive(st_filter_t f, char **buf, int *buflen, int *nbuf) {
     st_filter_t scan;
Index: sm/storage_pgsql.c
===================================================================
--- sm/storage_pgsql.c	(revision 109)
+++ sm/storage_pgsql.c	(revision 110)
@@ -491,7 +491,7 @@
     cond = _st_pgsql_convert_filter(drv, owner, filter);
     log_debug(ZONE, "generated filter: %s", cond);
 
-    PGSQL_SAFE(buf, strlen(type) + strlen(cond) + 20, buflen);
+    PGSQL_SAFE(buf, strlen(type) + strlen(cond) + 23, buflen);
     sprintf(buf, "DELETE FROM \"%s\" WHERE %s;", type, cond);
     free(cond);