Hardware designed for bitmap indexes?

Question

This is just a matter of curiosity. Let's say you have a database table with 1 m rows in it, and you want to make queries often, such as searching for men or women, the USA or non-Americans, voters or non-voters, etc., This is clearly very effective for determining a raster index for a table in which each bit represents one or one condition.

However, to execute the query, you still have to scan (possibly) the entire index that executes the bit and select the appropriate rows.

My question is, is there some kind of storage optimized for the bitmap, so that the bit channels are pre-created in the hardware? I guess it looks like knitting needles picking up punch cards from an old directory system. In other words, instead of going through the lines through the memory cells, the chip can simply pull out the corresponding lines in electronic form, because there are hardware connections for each bit channel? I have a feeling that the brain should work something like this. If I think of “all blue objects” and then limit it to “all long blue objects” and then “all long blue heavy objects”, my brain does it effortlessly and I’m sure that it doesn’t look at all objects, which I know about every time. Seem to be,that there are some neurons that provide paths for different dimensions for quick searching. I'm just wondering if there is anything like that in the hardware world?

Thank!

Answer 1

Why invent something that is already there?

Content Address Memory

Answer 2

You could connect some logic to accomplish this (for example, using programmable logic devices ), but you will need a large number of logic elements and connections, which makes such circuits probably expensive for large databases.

For example, it would be necessary to construct a correspondence logic (this bit is selected on? What is required value?) In each line, giving you one signal (selected / not selected) for each line.

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