Understanding was terminated by signal 9: Killed

2021-10-19 21:01:41 UTC::@:[24755]:LOG:  checkpoint complete: wrote 110375 buffers (22.3%); 0 WAL file(s) added, 0 removed, 14 recycled; write=269.809 s, sync=0.208 s, total=270.089 s; sync files=30, longest=0.200 s, average=0.007 s; distance=1020117 kB, estimate=1020117 kB
2021-10-19 21:07:11 UTC::@:[24755]:LOG:  checkpoint starting: time
2021-10-19 21:10:37 UTC::@:[24752]:LOG:  server process (PID 25813) was terminated by signal 9: Killed
2021-10-19 21:10:37 UTC::@:[24752]:DETAIL:  Failed process was running: refresh materialized view concurrently stats.vwm_d with data;
2021-10-19 21:10:37 UTC::@:[24752]:LOG:  terminating any other active server processes
2021-10-19 21:10:37 UTC::@:[24758]:WARNING:  terminating connection because of crash of another server process
2021-10-19 21:10:37 UTC::@:[24758]:DETAIL:  The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory.
2021-10-19 21:10:37 UTC::@:[24758]:HINT:  In a moment you should be able to reconnect to the database and repeat your command.
2021-10-19 21:10:37 UTC::@:[24752]:LOG:  archiver process (PID 24759) exited with exit code 2
2021-10-19 21:10:37 UTC::@:[24752]:LOG:  all server processes terminated; reinitializing
2021-10-19 21:10:37 UTC::@:[23697]:LOG:  database system was interrupted; last known up at 2021-10-19 21:01:41 UTC
2021-10-19 21:10:37 UTC::@:[23697]:LOG:  database system was not properly shut down; automatic recovery in progress
2021-10-19 21:10:37 UTC::@:[23697]:LOG:  redo starts at 611/C8668F30
2021-10-19 21:10:42 UTC::@:[23697]:LOG:  invalid record length at 612/310: wanted 24, got 0
2021-10-19 21:10:42 UTC::@:[23697]:LOG:  redo done at 612/2D8
2021-10-19 21:10:42 UTC::@:[23697]:LOG:  checkpoint starting: end-of-recovery immediate
2021-10-19 21:10:45 UTC:127.0.0.1(28416):rdsadmin@rdsadmin:[23907]:FATAL:  the database system is in recovery mode
2021-10-19 21:10:45 UTC:127.0.0.1(28418):rdsadmin@rdsadmin:[23908]:FATAL:  the database system is in recovery mode
2021-10-19 21:10:46 UTC::@:[23697]:LOG:  checkpoint complete: wrote 88487 buffers (17.8%); 0 WAL file(s) added, 0 removed, 2 recycled; write=3.986 s, sync=0.015 s, total=4.015 s; sync files=40, longest=0.008 s, average=0.001 s; distance=910940 kB, estimate=910940 kB
2021-10-19 21:10:46 UTC::@:[24752]:LOG:  database system is ready to accept connections
2021-10-19 21:15:46 UTC::@:[23909]:LOG:  checkpoint starting: time
2021-10-19 21:15:46 UTC::@:[23909]:LOG:  checkpoint complete: wrote 3 buffers (0.0%); 0 WAL file(s) added, 1 removed, 0 recycled; write=0.366 s, sync=0.005 s, total=0.383 s; sync files=2, longest=0.003 s, average=0.003 s; distance=5 kB, estimate=5 kB
2021-10-19 21:20:47 UTC::@:[23909]:LOG:  checkpoint starting: time
2021-10-19 21:20:52 UTC::@:[23909]:LOG:  checkpoint complete: wrote 51 buffers (0.0%); 0 WAL file(s) added, 1 removed, 0 recycled; write=4.987 s, sync=0.004 s, total=5.004 s; sync files=29, longest=0.004 s, average=0.001 s; distance=65682 kB, estimate=65682 kB
2021-10-19 21:25:47 UTC::@:[23909]:LOG:  checkpoint starting: time
2021-10-19 21:25:51 UTC::@:[23909]:LOG:  checkpoint complete: wrote 47 buffers (0.0%); 0 WAL file(s) added, 1 removed, 0 recycled; write=4.587 s, sync=0.011 s, total=4.630 s; sync files=27, longest=0.011 s, average=0.001 s; distance=65528 kB, estimate=65667 kB
2021-10-19 21:29:44 UTC::@:[23909]:LOG:  checkpoint starting: wal
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