Questions tagged [bitmap-index]
20 questions
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Optimized Postgresql like and group by clause
Database: PostgresSQL PostgreSQL 12.11 (Ubuntu 12.11-0ubuntu0.20.04.1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0, 64-bit
RAM : 8 GB
Processor : i7 4510U (dual core 2 Ghz)
I would to like to optimized below…
Rizwan Patel
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When does PostgreSQL automatically create a Bitmap index for a table?
When does PostgreSQL automatically create a Bitmap index for a table?
I saw the following examples from PostgreSQL' documentation, and wonder why changing the value in WHERE could make a difference? Thanks.
EXPLAIN SELECT * FROM tenk1 WHERE unique1…
Tim
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Oracle - Design of data warehouse tables
I understand that it makes sense to store dimension tables as index organized tables and fact tables using bitmap indexes for the dimension columns, however what should be done in the scenario where a fact table is used within another fact table?…
Superdooperhero
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How does bitmap index speed up a query compared to btree index?
I think it will give you a better understanding about where I'm coming from by letting you know how I understand how Btree indices work fundamentally. I'm not a DBA and I'm asking this question as a layman with basic understanding of data…
supertonsky
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PostgreSQL: intersect index scans on the same index
Trying to solve this problem: Sql: choose all baskets containing a set of particular items
In other words there is a table:
tbl_basket_item
--
basketId itemId
1 2
1 3
1 4
2 3
2 4
3 2
3 4
itemId is indexed.
If I perform a scan on itemId=2, I'll…
Denis Kulagin
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