Hello,
Yes, you are right; this query is not a SELECT, it is an UPDATE query, there was a mistake in expressing it here. The columns I want to update here only operate on data from the last 3 months time interval.
I am also sharing the EXPLAIN ANALYZE output of the relevant query below:
Update on "TestTable1" t1 (cost=0.13..159114.84 rows=0 width=0) (actual time=0.007..0.008 rows=0 loops=1)
Update on "PartitionTable_2020_10" t1
Update on "PartitionTable_2020_11" t1
Update on "PartitionTable_2020_12" t1
Update on "PartitionTable_2021_01" t1
Update on "PartitionTable_2021_02" t1
Update on "PartitionTable_2021_03" t1
Update on "PartitionTable_2021_04" t1
Update on "PartitionTable_2021_05" t1
Update on "PartitionTable_2021_06" t1
Update on "PartitionTable_2021_07" t1
Update on "PartitionTable_2021_08" t1
Update on "PartitionTable_2021_09" t1
Update on "PartitionTable_2021_10" t1
Update on "PartitionTable_2021_11" t1
Update on "PartitionTable_2021_12" t1
Update on "PartitionTable_2022_01" t1
Update on "PartitionTable_2022_02" t1
Update on "PartitionTable_2022_03" t1
Update on "PartitionTable_2022_04" t1
Update on "PartitionTable_2022_05" t1
Update on "PartitionTable_2022_06" t1
Update on "PartitionTable_2022_07" t1
Update on "PartitionTable_2022_08" t1
Update on "PartitionTable_2022_09" t1
Update on "PartitionTable_2022_10" t1
Update on "PartitionTable_2022_11" t1
Update on "PartitionTable_2022_12" t1
Update on "PartitionTable_2023_01" t1
Update on "PartitionTable_2023_02" t1
Update on "PartitionTable_2023_03" t1
Update on "PartitionTable_2023_04" t1
Update on "PartitionTable_2023_05" t1
Update on "PartitionTable_2023_06" t1
Update on "PartitionTable_2023_07" t1
Update on "PartitionTable_2023_08" t1
Update on "PartitionTable_2023_09" t1
Update on "PartitionTable_2023_10" t1
Update on "PartitionTable_2023_11" t1
Update on "PartitionTable_2023_12" t1
Update on "PartitionTable_2024_01" t1
Update on "PartitionTable_2024_02" t1
Update on "PartitionTable_2024_03" t1
Update on "PartitionTable_2024_04" t1
Update on "PartitionTable_2024_05" t1
Update on "PartitionTable_2024_06" t1
Update on "PartitionTable_2024_07" t1
Update on "PartitionTable_2024_08" t1
Update on "PartitionTable_2024_09" t1
Update on "PartitionTable_2024_10" t2
Update on "PartitionTable_2024_11" t3
Update on "PartitionTable_2024_12" t4
Update on "PartitionTable_2025_01" t5
Update on "PartitionTable_2025_02" t1
Update on "PartitionTable_2025_03" t1
Update on "PartitionTable_2025_04" t1
Update on "PartitionTable_2025_05" t1
Update on "PartitionTable_2025_06" t1
Update on "PartitionTable_2025_07" t1
Update on "PartitionTable_2025_08" t1
Update on "PartitionTable_2025_09" t1
Update on "PartitionTable_2025_10" t1
Update on "PartitionTable_2025_11" t1
Update on "PartitionTable_2025_12" t1
Update on "DefaultPartitionTable" t1
-> Nested Loop (cost=0.13..159114.84 rows=1 width=53) (actual time=0.006..0.006 rows=0 loops=1)
-> Seq Scan on "TempTable1" tmp (cost=0.00..19.20 rows=920 width=31) (actual time=0.006..0.006 rows=0 loops=1)
-> Append (cost=0.13..172.29 rows=64 width=38) (never executed)
Subplans Removed: 60
-> Index Scan using partitiontable_2024_10_pkey on "PartitionTable_2024_10" t2 (cost=0.43..4.21 rows=1 width=38) (never executed)
Index Cond: (("Col1" = tmp."Col2") AND ("Col3" >= (CURRENT_DATE - '3 mons'::interval)) AND ("Col3" <= CURRENT_DATE))
Filter: ((NOT "IsDeleted") AND ("Col4" = tmp."Col5"))
-> Index Scan using partitiontable_2024_11_pkey on "PartitionTable_2024_11" t3 (cost=0.43..4.23 rows=1 width=38) (never executed)
Index Cond: (("Col1" = tmp."Col2") AND ("Col3" >= (CURRENT_DATE - '3 mons'::interval)) AND ("Col3" <= CURRENT_DATE))
Filter: ((NOT "IsDeleted") AND ("Col4" = tmp."Col5"))
-> Index Scan using partitiontable_2024_12_pkey on "PartitionTable_2024_12" t4 (cost=0.43..4.34 rows=1 width=38) (never executed)
Index Cond: (("Col1" = tmp."Col2") AND ("Col3" >= (CURRENT_DATE - '3 mons'::interval)) AND ("Col3" <= CURRENT_DATE))
Filter: ((NOT "IsDeleted") AND ("Col4" = tmp."Col5"))
-> Index Scan using partitiontable_2025_01_pkey on "PartitionTable_2025_01" t5 (cost=0.43..3.72 rows=1 width=38) (never executed)
Index Cond: (("Col1" = tmp."Col2") AND ("Col3" >= (CURRENT_DATE - '3 mons'::interval)) AND ("Col3" <= CURRENT_DATE))
Filter: ((NOT "IsDeleted") AND ("Col4" = tmp."Col5"))
Planning Time: 3.860 ms
Execution Time: 0.066 ms
Thank you for your interest and support.
Good work,
Eşref Halıcıoğlu
----------------
To: Eşref Halıcıoğlu (esref.halicioglu@xxxxxxxxxxxxxx);
Cc: pgsql-general@xxxxxxxxxxxxxxxxxxxx;
Subject: About PostgreSQL Query Plan;
13.01.2025, 18:42, "hubert depesz lubaczewski" <depesz@xxxxxxxxxx>:
On Mon, Jan 13, 2025 at 05:26:09PM +0300, Eşref Halıcıoğlu wrote:
Hello,
I have a query in PostgreSQL and I want this query to retrieve only data from the last 3 months. However, when I examine the query
plan, I see that all partitions are listed.
Please note that your explain is for update, not select (which
"retrieve" in your mail would suggest).
This raises a few questions in my mind:
• Are all partitions really being accessed, or only the partitions of the last 3 months are being accessed while the other
partitions have to be shown in the query plan?
Not really possible to tell without reading explain *analyze*.
Potentially all. But perhaps just fewer.
Best regards,
depesz
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