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Db System Implementation

Stephen M. Reaves

::

2023-06-22

Notes about Lesson 9 of CS-6400

Summary

Data First Implementation

LAMP/WAMP/MAMP stack demos

I don’t really understand the point of this section

To index Or Not

Many things to consider:

Size of Table

Consider the following table:

RegularUser(
  Email varchar(50),
  Sex char(1),
  Birthdate datetime,
  CurrentCity varchar(50),
  Hometown varchar(50),
);

And assume our DBMS uses 4k blocks and tries to fill them to 80%.

That would give us the following stats:

Reads v. Writes

In general, indexing makes reads faster and writes slower.

Updates (and some other writes) require first reading, then writing. Inserting generally only needs to write.

Advice

Leo’s Advice: