3395663 - OOM Error Causes "Error in DDL, nametab for <table> not activated" During S4 Conversion

During S/4HANA conversion phase 'MAIN_SWITCH/PARMVNT_BAS_TABS' you face an error similar to the one below.

2 ETP401 ----------------------------------------------------------------------
 activating Nametab "<table>":
 statements:
2 ETP000 ALTER TABLE "SAPABAP1"."APQD" ALTER TYPE ROW
executed ( "0:11:06 (666.266481 sec)" )
Retcode 1: SQL-error "129-transaction rolled back by an internal error: Detected
a full rollback situation during statement rollback" in DDL statement for "APQD"
 --------------- DB-ROLLBACK() ---------------
12:23:41: error in DDL, nametab for "APQD" not activated 

When reviewing HANA DB traces from the same timeframe, we observe an out of memory (OOM) event which causes the rollback.

2023-10-23 23:03:55.204374 w Memory           mmPoolAllocator.cpp(01217) : Out of memory for Pool/LargeObjectPool, size 32768B, alignment=1B, flags 0x0, reason STATEMENT_MEMORY_LIMIT_FROM_GLOBAL_CONFIG
   0: 0x00007fc8686e85dd in Diagnose::CallStack::fillTrace(ltt::basic_ostream<char, ltt::char_traits<char> >&, void**, unsigned long, Diagnose::RegisterSet const*, void const*, bool, unsigned long, Diagnose::CallStackModifier*)+0x269 at Basis/Diagnose/impl/CallStack.cpp:765 (libhdbbasis.so)
   1: 0x00007fc8686ed549 in ltt::operator<<(ltt::basic_ostream<char, ltt::char_traits<char> >&, Diagnose::CallStack const&) [clone .part.0]+0x25 at Basis/Diagnose/impl/CallStackManager.cpp:939 (libhdbbasis.so)
   2: 0x00007fc868d33777 in ltt::operator<<(ltt::basic_ostream<char, ltt::char_traits<char> >&, Diagnose::CallStack const&) [clone .constprop.0]+0x23 at Basis/System/impl/IsInMain.cpp:179 (libhdbbasis.so)
   3: 0x00007fc868b8ea26 in MemoryManager::PoolAllocator::oomHandling(unsigned long, unsigned long, bool)+0x212 at Basis/MemoryManager/impl/mmPoolAllocator.cpp:1217 (libhdbbasis.so)

2023-10-23 23:05:25.592899 e Row_Engine       qx_trex.cc(05867) : table type conversion failed : ltt::exception = Allocation failed $REASON$

2023-10-23 23:09:53.974839 e OOMFlagPropagati JobExecutorUtil.cpp(00231) : JobFinalObjectImpl::checkAndThrowException: oom flag transferred
2023-10-23 23:09:53.975050 e ddl              qx_trex.cc(06136) : Failed to run conversion: transaction rolled back by an internal error
2023-10-23 23:11:24.238006 e OOM_Notification Statement.cc(04624) : oom exception occurred at 'isrgehq-ha-hsr:30003': conn_id=306256, stmt_id=1315359523305194, stmt_hash=51a2e1ac9dbabb56048c42c638119ec4, sql=ALTER TABLE "SAPPRD"."APQD" ALTER TYPE ROW 

• SAP HANA, Platform Edition 1.0
• SAP HANA, Platform Edition 2.0
• SAP S/4 HANA 2020

OOM, Error in DDL, nametab, S4 conversion, S/4 HANA, APQD, rollback, MAIN_SWITCH/PARMVNT_BAS_TABS, statement_memory_limit, target, source,MemoryManager, alter table, rolled back , KBA , HAN-DB , SAP HANA Database , BC-UPG-TLS-TLA , Upgrade tools for ABAP , HAN-LM-UPG-SAP , Upgrade of SAP Systems on HANA , Problem