These engines were developed for scenarios when you need to quickly write many small tables (up to about 1 million rows) and read them later as a whole.
During `INSERT` query the table is locked, and other queries for reading and writing data both wait for unlocking. If there are no writing data queries, any number of reading data queries can be performed concurrently.
The `TinyLog` engine is the simplest in the family and provides the poorest functionality and lowest efficiency. The `TinyLog` engine does not support a parallel reading of data. It reads the data slower than other engines of the family that have parallel reading, and it uses almost as many descriptors as the `Log` engine because it stores each column in a separate file. Use it in simple low-load scenarios.
The `Log` and `StripeLog` engines support parallel reading of data. When reading data ClickHouse uses multiple threads. Each thread processes separated data block. The `Log` engine uses the separate file for each column of the table. The `StripeLog` stores all the data in one file. Thus the `StripeLog` engine uses fewer descriptors in the operating system, but the `Log` engine provides a more efficient reading of the data.
