I’ve been using indexes on my MySQL databases for a while now but never properly learnt about them. Generally I put an index on any fields that I will be searching or selecting using a WHERE clause but sometimes it doesn’t seem so black and white.
What are the best practices for MySQL indexes?
Example situations/dilemmas:
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If a table has six columns and all of them are searchable, should I index all of them or none of them?
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What are the negative performance impacts of indexing?
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If I have a VARCHAR 2500 column which is searchable from parts of my site, should I index it?