Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the

free space information is stored in a dedicated FSM relation fork, with each
relation (except for hash indexes; they don't use FSM).

This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any
trace of them from the backend, initdb, and documentation.

Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also
introduce a new variant of the get_raw_page(regclass, int4, int4) function in
contrib/pageinspect that let's you to return pages from any relation fork, and
a new fsm_page_contents() function to inspect the new FSM pages.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/include/storage/indexfsm.h b/src/include/storage/indexfsm.h
new file mode 100644
index 00000000000..76bb26f7bc8
--- /dev/null
+++ b/src/include/storage/indexfsm.h
@@ -0,0 +1,27 @@
+/*-------------------------------------------------------------------------
+ *
+ * indexfsm.h
+ *	  POSTGRES free space map for quickly finding an unused page in index
+ *
+ *
+ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/storage/indexfsm.h,v 1.1 2008/09/30 10:52:14 heikki Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef INDEXFSM_H_
+#define INDEXFSM_H_
+
+#include "utils/rel.h"
+
+extern void InitIndexFreeSpaceMap(Relation rel);
+
+extern BlockNumber GetFreeIndexPage(Relation rel);
+extern void RecordFreeIndexPage(Relation rel, BlockNumber page);
+extern void RecordUsedIndexPage(Relation rel, BlockNumber page);
+
+extern void IndexFreeSpaceMapTruncate(Relation rel, BlockNumber nblocks);
+
+#endif   /* INDEXFSM_H */