MySQL - slow queries with multiple conditions despite indexing

Question

I have a table with stock prices. The schema looks like this:

In table 'data_1d' there is a unique index ticker_timestamp for ticker_id and timestamp. And a primary index on timestamp_id.

There are ~6.3M rows in 'data_1d'.

This query takes 4+ secs:

select * from data_1d where timestamp_id=1387 and open_close>20

Explain:

And it's 20-30 secs if I search for a range of timestamps.

If I search for by only one criteria, timestamp or open_close, it takes 0.1-0.6 secs.

For example:

select * from data_1d where timestamp_id=1387

OR

select * from data_1d where and open_close>20

What can I do to improve the performance here?

Thanks.

EDIT: I didn't use statement to create the tables but they should be understandable from the schema. But these are the keys being used in them

tickers primary key: id

timestamps_1d primary key: id unique index: timestamp

data_1d ticker_id - references tickers.id timestamp_id - references timestamps_1d.id unique index (or 2 cols, ticker_id and timestamp_id): ticker_timestamps

Answer 1

Do not "normalize" continuous values, such as timestamps, floats, dates, etc.

"And it's 20-30 secs if I search for a range of timestamps." -- show us the query. For that matter, to help you in making the write schema and indexes, let's see samples of all the important queries.

"unique index: timestamp" -- Surely you have two different stocks with the same timestamp??

There is at least one ticker that won't fit in DECIMAL(7,2) : NYSE:BRKA. INT won't suffice for an occasional Volume.

select * from data_1d where and open_close>20 has a syntax error.