What would be the best database server to store value of PI?

Question

Say 100 million digits, one string. The purpose is to query the DB to find recurrence of a search string. While I know that LONGTEXT type in MySQL would allow for the string to be stored, I am not sure that querying the substring would actually result in acceptable performances. Would a NoSQL key-value model would perform better? Any suggestion, experience (does not have to be PI..).

Answer 1

This may be taking you in the wrong direction but...

Using MySQL seems to be a high-overhead way of solving the specific problem of finding a string in a file.

100M digits, 8 bytes each, is only 100MB. In Python, you could write the file as a sequence of bytes, each byte representing an ascii number. Or, you could pack them into nibbles (4 bits will cover digits 0-9).

In Python, you can read the file using:

fInput = open(<yourfilenamehere>, "rb")
fInput.seek(number_of_digit_you_want)
fInput.read(1)  # to get a single byte

From this, it is easy to build a search solution to seek out a specific string.

Again, mySQL might be the way to go but, for your application, a non-high-overhead method might be the ticket.