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Tag: indexing

How to make postgres not use a particular index?

I have the following query: As you can see, the cost of the last index scan on chaindata_tokentransfer_chain_id_block_number_tx_eeeac2a4_idx is very high. And the query is timing out. If I remove the filter on chain_id and block_number from the query, then the query is executing in a reasonable amount of time. Since this new less constrained query is working, I’d expect

How does a multi-column index work in MySQL?

More specifically, what data structure does MYSQL use for multi-column indexing? I know MYSQL use Btree for indexing, which can only index one column. How does multi-column indexing work then? Answer Think of a MySQL “composite” index this way. Concatenate all the columns in the index together, then build an BTree index on that ‘single’ string. Some related comments: Once

Multi-column Index on a filter & sort by query

I am executing an query of type: Query: Table: entity also has an index (Btree) on it as such – Index: But it seems that this type of index is of no use on the above query. Can anyone suggest what kind of index would better serve this type of use-case? Some Additional Information – The Table is quite huge,

Does Adding Indexes speed up String Wildcard % searches?

We are conducting a wildcard search on a database table with column string. Does creating a non-clustered index on columns help with wildcard searches? Will this improve performance? Proposed Index: for this query Currently using Microsoft SQL Server 2019. Answer Creating a normal index will not help(*), but a full-text index will, though you would have to change your query