Most Efficient Way to Create an Index in Postgres
2016年10月6日 · Create index when table is created, then load each file into table; or; Create index after all files have been loaded into the table. The table data itself is about 45 Gigabytes. The index is about 12 Gigabytes. I'm using a standard index. It is created like this: CREATE INDEX idx_name ON table_name (column_name); My data loading uses COPY FROM.
postgresql - How to add an index with WHERE-clause in Postgres
2016年3月1日 · Just create the index. create index concurrently em_openorder_idx on line (m_product_id,org_id,date) I gues you want realize a query similar to this. EXPLAIN ANALYZE SELECT * FROM line WHERE m_product_id = @id AND date>=now()-90 This will use the index and should be very fast.
Can PostgreSQL index array columns? - Stack Overflow
2010年10月30日 · How to create an index for elements of an array in PostgreSQL? Compare arrays for equality, ignoring order of elements As for the UNIQUE constraint in your question that went unanswered: That's implemented with a btree index on the whole array value (like you suspected) and does not help with the search for elements at all.
sql - PostgreSQL Index Usage Analysis - Stack Overflow
2010年7月23日 · PoWA seems like an interesting tool for PostgreSQL 9.4+. It collects statistics, visualizes them, and suggests indexes. It uses the pg_stat_statements extension. PoWA is PostgreSQL Workload Analyzer that gathers performance stats and provides real-time charts and graphs to help monitor and tune your PostgreSQL servers.
How to SELECT data from a postgreSQL INDEX? - Stack Overflow
2017年5月6日 · Data in the index is internal to PostgreSQL, and it's not accessible to the outside world. You can introspect your index definitions (using pg_indexes table or pg_get_indexdef function), but you can't look up what's actually stored in those.
sql - Postgres indexes statistics - Stack Overflow
2018年5月17日 · With a normal index, you don't need to collect any statistics for the index, because all you need to know is the distribution of the column values. So it does not matter if you ANALYZE before or after CREATE INDEX. The exception to …
postgresql - About clustered index in postgres - Stack Overflow
2011年1月25日 · In PostgreSQL the clustered attribute is held in the metadata of the corresponding index, rather than the relation itself. It is the indisclustered attribute in pg_index catalogue. Note, however, that clustering relations within postgres is a one-time action: even if the attribute is true, updates to the table do not maintain the sorted nature ...
How do I force Postgres to use a particular index?
One thing to note with PostgreSQL; where you are expecting an index to be used and it is not being used, is to VACUUM ANALYZE the table. VACUUM ANALYZE schema.table; This updates statistics used by the planner to determine the most efficient way to execute a query. Which may result in the index being used. Another thing to check is the types.
PostgreSQL index size and value number - Stack Overflow
2017年9月29日 · Eg let me have a partial index, so the "number of rows" in the index is different from the number of rows in the table. I can check estimations with EXPLAIN (of course you have to repeat the WHERE clause for that) checking the rows=66800 in Index Only Scan using gives me an idea on the number of rows in that index (actually it is rows=64910 ...
Retrieve a progress of index creation process in PostgreSQL
2014年2月4日 · Consider long-running query in PostgreSQL of index creation, smth like that: CREATE INDEX some_idx ON some_table USING btree (some_varchar_column COLLATE pg_catalog."default"); The question is: how to retrieve the progress of this query process? Is it possible or not? It is interesting to know the way in both cases: using pgAdmin