# Materialized Views and Secondary Indexes

This simulation shows four ways that ScyllaDB can find rows by a column that is
not the partition key:

* Materialized view
* Global secondary index
* Local secondary index
* `ALLOW FILTERING`

For each mode, the simulation shows the CQL statements, the base table and the
table that ScyllaDB derives from it, and the write and read paths through the
cluster. Use the **Driver** control to compare a smart (token-aware) driver
with a driver that is not token-aware.

#### NOTE
This is an educational simulation. It is simplified, and it does not show
all of the ScyllaDB internals exactly.

Source code: [tzach/scylladb-mv-viz on GitHub](https://github.com/tzach/scylladb-mv-viz)