Re: BUG #19078: Segfaults in tts_minimal_store_tuple() following pg_upgrade

Haven't managed to reproduce it consistently so far.
Perhaps we could use the existing dump to investigate.
I'm unfamiliar with Postgres internals. If it would be useful,
could you walk me through the structures I need to capture?

> (gdb) frame 2
> #2  0x0000555fe8566ec2 in agg_retrieve_hash_table_in_memory (aggstate=aggstate@entry=0x55601c7567d0) at ./build/../src/include/executor/executor.h:176
> 176	in ./build/../src/include/executor/executor.h
> (gdb) print *perhash
> $83 = {hashtable = 0x55601c182ac8, hashiter = {cur = 10, end = 43, done = false}, hashslot = 0x55601c765bb0, hashfunctions = 0x55601c765b28,
>   eqfuncoids = 0x55601c765b18, numCols = 2, numhashGrpCols = 2, largestGrpColIdx = 4, hashGrpColIdxInput = 0x55601c7659f0, hashGrpColIdxHash = 0x55601c765a00,
>   aggnode = 0x55601eba19f8}
> (gdb) print *hashtable->hashtab
> $84 = {size = 16, members = 4, sizemask = 15, grow_threshold = 14, data = 0x55601c182b98, ctx = 0x55601c1819b0, private_data = 0x55601c182ac8}
> (gdb) print *entry
> $86 = {firstTuple = 0x1b, status = 1, hash = 21856}
 
Does it look suspicious?
perhash->hashiter->end=43, hashtable->hashtab->size=16, 43-16=0x1b

Some more details from that step:

> (gdb) info locals
> hashslot = 0x55601c765bb0
> hashtable = 0x55601c182ac8
> i = <optimized out>
> econtext = 0x55601c756f00
> peragg = 0x55601c765198
> pergroup = <optimized out>
> entry = 0x55601c182e48
> firstSlot = 0x55601c763e48
> result = <optimized out>
> perhash = 0x55601c764e50
> (gdb) print *aggstate
> $87 = {ss = {ps = {type = T_AggState, plan = 0x55601eb9bb18, state = 0x55601b1a60a8, ExecProcNode = 0x555fe8567890 <ExecAgg>,
>       ExecProcNodeReal = 0x555fe8567890 <ExecAgg>, instrument = 0x0, worker_instrument = 0x0, worker_jit_instrument = 0x0, qual = 0x0, lefttree = 0x55601c757008,
>       righttree = 0x0, initPlan = 0x0, subPlan = 0x0, chgParam = 0x0, ps_ResultTupleDesc = 0x55601c763f50, ps_ResultTupleSlot = 0x55601c764758,
>       ps_ExprContext = 0x55601c756f00, ps_ProjInfo = 0x55601c764860, async_capable = false, scandesc = 0x55601c762fa0, scanops = 0x555fe8bd0f20 <TTSOpsVirtual>,
>       outerops = 0x555fe8bd0f20 <TTSOpsVirtual>, innerops = 0x0, resultops = 0x555fe8bd0f20 <TTSOpsVirtual>, scanopsfixed = true, outeropsfixed = true,
>       inneropsfixed = false, resultopsfixed = true, scanopsset = true, outeropsset = true, inneropsset = false, resultopsset = true}, ss_currentRelation = 0x0,
>     ss_currentScanDesc = 0x0, ss_ScanTupleSlot = 0x55601c763e48}, aggs = 0x55601c7628a8, numaggs = 1, numtrans = 1, aggstrategy = AGG_HASHED,
>   aggsplit = AGGSPLIT_SIMPLE, phase = 0x55601c764d70, numphases = 1, current_phase = 0, peragg = 0x55601c765198, pertrans = 0x55601c765220,
>   hashcontext = 0x55601c756df8, aggcontexts = 0x55601c756bd8, tmpcontext = 0x55601c756be8, curaggcontext = 0x55601c756df8, curperagg = 0x0,
>   curpertrans = 0x55601c765220, input_done = false, agg_done = false, projected_set = -1, current_set = 1, grouped_cols = 0x55601c765040,
>   all_grouped_cols = 0x55601c7650b8, colnos_needed = 0x55601c7656b0, max_colno_needed = 9, all_cols_needed = true, maxsets = 1, phases = 0x55601c764d70, sort_in = 0x0,
>   sort_out = 0x0, sort_slot = 0x0, pergroups = 0x0, grp_firstTuple = 0x0, table_filled = true, num_hashes = 4, hash_metacxt = 0x55601c1819b0,
>   hash_tablecxt = 0x55601c1839c0, hash_tapeset = 0x0, hash_spills = 0x0, hash_spill_rslot = 0x55601c765470, hash_spill_wslot = 0x55601c765578, hash_batches = 0x0,
>   hash_ever_spilled = false, hash_spill_mode = false, hash_mem_limit = 2147483648, hash_ngroups_limit = 10324440, hash_planned_partitions = 0,
>   hashentrysize = 138.26865671641792, hash_mem_peak = 81920, hash_ngroups_current = 67, hash_disk_used = 0, hash_batches_used = 1, perhash = 0x55601c764df8,
>   hash_pergroup = 0x55601c765428, all_pergroups = 0x55601c765428, shared_info = 0x0}
> (gdb) print *hashslot
> $88 = {type = T_TupleTableSlot, tts_flags = 24, tts_nvalid = 0, tts_ops = 0x555fe8bd0e20 <TTSOpsMinimalTuple>, tts_tupleDescriptor = 0x55601c765a10,
>   tts_values = 0x55601c765c20, tts_isnull = 0x55601c765c30, tts_mcxt = 0x55601b1a5fb0, tts_tid = {ip_blkid = {bi_hi = 65535, bi_lo = 65535}, ip_posid = 0},
>   tts_tableOid = 0}
> (gdb) print *hashtable
> $89 = {hashtab = 0x55601c182b50, numCols = 2, keyColIdx = 0x55601c765a00, tab_hash_expr = 0x55601c182eb0, tab_eq_func = 0x55601c1833e8,
>   tab_collations = 0x55601eba1b20, tablecxt = 0x55601c1839c0, tempcxt = 0x55601c17b980, additionalsize = 16, tableslot = 0x55601c182da8, inputslot = 0x55601c765bb0,
>   in_hash_expr = 0x55601c182eb0, cur_eq_func = 0x55601c1833e8, exprcontext = 0x55601c14b7f8}
> (gdb) print *econtext
> $90 = {type = T_ExprContext, ecxt_scantuple = 0x0, ecxt_innertuple = 0x0, ecxt_outertuple = 0x55601c763e48, ecxt_per_query_memory = 0x55601b1a5fb0,
>   ecxt_per_tuple_memory = 0x55601c1859d0, ecxt_param_exec_vals = 0x55601b42bcf0, ecxt_param_list_info = 0x55601b0f7a78, ecxt_aggvalues = 0x55601c762e88,
>   ecxt_aggnulls = 0x55601c765188, caseValue_datum = 0, caseValue_isNull = true, domainValue_datum = 0, domainValue_isNull = true, ecxt_oldtuple = 0x0,
>   ecxt_newtuple = 0x0, ecxt_estate = 0x55601b1a60a8, ecxt_callbacks = 0x0}
> (gdb) print *peragg
> $91 = {aggref = 0x55601eb9c170, transno = 0, finalfn_oid = 0, finalfn = {fn_addr = 0x0, fn_oid = 0, fn_nargs = 0, fn_strict = false, fn_retset = false,
>     fn_stats = 0 '\000', fn_extra = 0x0, fn_mcxt = 0x0, fn_expr = 0x0}, numFinalArgs = 1, aggdirectargs = 0x0, resulttypeLen = 4, resulttypeByVal = true,
>   shareable = false}
> (gdb) print *firstSlot
> $92 = {type = T_TupleTableSlot, tts_flags = 16, tts_nvalid = 9, tts_ops = 0x555fe8bd0f20 <TTSOpsVirtual>, tts_tupleDescriptor = 0x55601c762fa0,
>   tts_values = 0x55601c763e90, tts_isnull = 0x55601c763ed8, tts_mcxt = 0x55601b1a5fb0, tts_tid = {ip_blkid = {bi_hi = 65535, bi_lo = 65535}, ip_posid = 0},
>   tts_tableOid = 0}