I’m faced with the following and I’m not sure what’s best practice. Consider the following table (which will get large): id PK | giver_id FK | recipient_id FK | date I’m using InnoDB and from what I understand, it creates indices automatically for the two foreign key columns. However, …
Tag: indexing
List columns with indexes in PostgreSQL
I would like to get the columns that an index is on in PostgreSQL. In MySQL you can use SHOW INDEXES FOR table and look at the Column_name column. Does anything like this exist for PostgreSQL? I’ve tried d at the psql command prompt (with the -E option to show SQL) but it doesn’t show the informat…
Force index use in Oracle
I encountered this question in an interview and had no clue how to answer: There is a table which has a index on a column, and you query: The query takes too long, and you find out that the index is not being used. If you think the performance of the query will be better using the index, how could
Can I add a UNIQUE constraint to a PostgreSQL table, after it’s already created?
I have the following table: tickername | tickerbbname | tickertype ————+—————+———— USDZAR | USDZAR Curncy | C EURCZK | EURCZK Curncy | C EURPLN | EURPLN …
What are Covering Indexes and Covered Queries in SQL Server?
Can you explain the concepts of, and relationship between, Covering Indexes and Covered Queries in Microsoft’s SQL Server? Answer A covering index is one which can satisfy all requested columns in a query without performing a further lookup into the clustered index. There is no such thing as a covering …