![]() ![]() The system is designed to disallow creating product duplicates (by `products.name`), unless it was already existing before and has been deleted (so there may be many deleted products with the same `name`, but different `deleted_at` timestamp). Deleting the product from the application doesnât remove it permanently from the database, but instead marks it as deleted by populating the `deleted_at` column with a timestamp. With PostgreSQL, we can create covering indexes using the INCLUDE clause, which are types of indexes that specify a list of columns to be included in the index. Edit: a related issue is described in this question. Check your CONSTRAINTS via select from informationschema.tableconstraints Then if you find one, you should be able to drop it like: ALTER TABLE DROP CONSTRAINT .![]() One of these is when performing unique indexing on multiple columns, where at least one of them is null.Ĭonsider the following scenario: You have a database table named `products` which works with a custom implementation of soft delete mechanism, so it includes columns: `name` and `deleted_at`. You may be able to remove the unique CONSTRAINT, and not the INDEX itself. However, when weâre working with database indexes, it can be easy to miss something, or fall into the trap of a tricky outlying case. Especially when the amount of data grows rapidly, well designed database architecture really pays off. An index always contains some kind of a pointer to the row (ctid in PostgreSQL, row pointer in MyISAM, primary key/uniquifier in InnoDB) and the leaves are ordered on these pointers, so in fact every index leaf is unique is some way (though it may not be obvious). (This limit can be altered when building PostgreSQL. ![]() Working correctly with database indexes is always the key to application performance and reliability. Indexes can have up to 32 columns, including INCLUDE columns. ![]()
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