Hello, While executing the below test case server crashed with Segfault 11 on master branch. I have enabled the CLOBBER_CACHE_ALWAYS in src/include/pg_config_manual.h
Issue is only reproducing on master branch. *Test Case:* CREATE TABLE sm_5_323_table (col1 numeric); CREATE INDEX sm_5_323_idx ON sm_5_323_table(col1); CLUSTER sm_5_323_table USING sm_5_323_idx; \! /PGClobber_build/postgresql/inst/bin/clusterdb -t sm_5_323_table -U edb -h localhost -p 5432 -d postgres *Test case output:* edb@edb:~/PGClobber_build/postgresql/inst/bin$ ./psql postgres psql (14devel) Type "help" for help. postgres=# CREATE TABLE sm_5_323_table (col1 numeric); CREATE TABLE postgres=# CREATE INDEX sm_5_323_idx ON sm_5_323_table(col1); CREATE INDEX postgres=# CLUSTER sm_5_323_table USING sm_5_323_idx; CLUSTER postgres=# \! /PGClobber_build/postgresql/inst/bin/clusterdb -t sm_5_323_table -U edb -h localhost -p 5432 -d postgres clusterdb: error: clustering of table "sm_5_323_table" in database "postgres" failed: server closed the connection unexpectedly This probably means the server terminated abnormally before or while processing the request. *Stack Trace:* Core was generated by `postgres: edb postgres 127.0.0.1(50978) CLUSTER '. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x000055e5c85ea0b4 in mdopenfork (reln=0x0, forknum=MAIN_FORKNUM, behavior=1) at md.c:485 485 if (reln->md_num_open_segs[forknum] > 0) (gdb) bt #0 0x000055e5c85ea0b4 in mdopenfork (reln=0x0, forknum=MAIN_FORKNUM, behavior=1) at md.c:485 #1 0x000055e5c85eb2f0 in mdnblocks (reln=0x0, forknum=MAIN_FORKNUM) at md.c:768 #2 0x000055e5c85eb61b in mdimmedsync (reln=0x0, forknum=forknum@entry=MAIN_FORKNUM) at md.c:930 #3 0x000055e5c85ec6e5 in smgrimmedsync (reln=<optimized out>, forknum=forknum@entry=MAIN_FORKNUM) at smgr.c:662 #4 0x000055e5c81ae28b in end_heap_rewrite (state=state@entry=0x55e5ca5d1d70) at rewriteheap.c:342 #5 0x000055e5c81a32ea in heapam_relation_copy_for_cluster (OldHeap=0x7f212ce41ba0, NewHeap=0x7f212ce41058, OldIndex=<optimized out>, use_sort=<optimized out>, OldestXmin=<optimized out>, xid_cutoff=<optimized out>, multi_cutoff=0x7ffcba6ebe64, num_tuples=0x7ffcba6ebe68, tups_vacuumed=0x7ffcba6ebe70, tups_recently_dead=0x7ffcba6ebe78) at heapam_handler.c:984 #6 0x000055e5c82f218a in table_relation_copy_for_cluster (tups_recently_dead=0x7ffcba6ebe78, tups_vacuumed=0x7ffcba6ebe70, num_tuples=0x7ffcba6ebe68, multi_cutoff=0x7ffcba6ebe64, xid_cutoff=0x7ffcba6ebe60, OldestXmin=<optimized out>, use_sort=<optimized out>, OldIndex=0x7f212ce40670, NewTable=0x7f212ce41058, OldTable=0x7f212ce41ba0) at ../../../src/include/access/tableam.h:1656 #7 copy_table_data (pCutoffMulti=<synthetic pointer>, pFreezeXid=<synthetic pointer>, pSwapToastByContent=<synthetic pointer>, verbose=<optimized out>, OIDOldIndex=<optimized out>, OIDOldHeap=16384, OIDNewHeap=<optimized out>) at cluster.c:908 #8 rebuild_relation (verbose=<optimized out>, indexOid=<optimized out>, OldHeap=<optimized out>) at cluster.c:604 #9 cluster_rel (tableOid=<optimized out>, indexOid=<optimized out>, params=<optimized out>) at cluster.c:427 #10 0x000055e5c82f2b7f in cluster (pstate=pstate@entry=0x55e5ca5315c0, stmt=stmt@entry=0x55e5ca510368, isTopLevel=isTopLevel@entry=true) at cluster.c:195 #11 0x000055e5c85fcbc6 in standard_ProcessUtility (pstmt=0x55e5ca510430, queryString=0x55e5ca50f850 "CLUSTER public.sm_5_323_table;", context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0, dest=0x55e5ca510710, qc=0x7ffcba6ec340) at utility.c:822 #12 0x000055e5c85fd436 in ProcessUtility (pstmt=pstmt@entry=0x55e5ca510430, queryString=<optimized out>, context=context@entry=PROCESS_UTILITY_TOPLEVEL, params=<optimized out>, queryEnv=<optimized out>, dest=dest@entry=0x55e5ca510710, qc=0x7ffcba6ec340) at utility.c:525 #13 0x000055e5c85f6148 in PortalRunUtility (portal=portal@entry=0x55e5ca570d70, pstmt=pstmt@entry=0x55e5ca510430, isTopLevel=isTopLevel@entry=true, setHoldSnapshot=setHoldSnapshot@entry=false, dest=dest@entry=0x55e5ca510710, qc=qc@entry=0x7ffcba6ec340) at pquery.c:1159 #14 0x000055e5c85f71a4 in PortalRunMulti (portal=portal@entry=0x55e5ca570d70, isTopLevel=isTopLevel@entry=true, setHoldSnapshot=setHoldSnapshot@entry=false, dest=dest@entry=0x55e5ca510710, altdest=altdest@entry=0x55e5ca510710, qc=qc@entry=0x7ffcba6ec340) at pquery.c:1305 #15 0x000055e5c85f8823 in PortalRun (portal=portal@entry=0x55e5ca570d70, count=count@entry=9223372036854775807, isTopLevel=isTopLevel@entry=true, run_once=run_once@entry=true, dest=dest@entry=0x55e5ca510710, altdest=altdest@entry=0x55e5ca510710, qc=0x7ffcba6ec340) at pquery.c:779 #16 0x000055e5c85f389e in exec_simple_query (query_string=0x55e5ca50f850 "CLUSTER public.sm_5_323_table;") at postgres.c:1185 #17 0x000055e5c85f51cf in PostgresMain (argc=argc@entry=1, argv=argv@entry=0x7ffcba6ec670, dbname=<optimized out>, username=<optimized out>) at postgres.c:4415 #18 0x000055e5c8522240 in BackendRun (port=<optimized out>, port=<optimized out>) at postmaster.c:4470 #19 BackendStartup (port=<optimized out>) at postmaster.c:4192 #20 ServerLoop () at postmaster.c:1737 #21 0x000055e5c85237ec in PostmasterMain (argc=<optimized out>, argv=0x55e5ca508fe0) at postmaster.c:1409 #22 0x000055e5c811a2cf in main (argc=3, argv=0x55e5ca508fe0) at main.c:209 Thanks. -- Regards, Neha Sharma