What is indexing at a high level?

< 1 min read

Indexing is a way to help the database find data faster without scanning the whole table.
It works like a book index — jump directly to the needed record.
In a customer report, filtering by customer_id was slow on a large table.
After adding an index on customer_id, the dashboard load time dropped significantly.
Indexes are best for columns used in filters, joins, and sorting like date or order_id.
But too many indexes slow down inserts and updates.
So I suggest indexing frequently searched fields, not every column.
I usually discuss usage patterns with the data team before requesting indexes.

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