Declarative tools.
WHAT SQL IS
A declarative language for querying and manipulating relational data.
WHY DECLARATIVE MATTERS
You describe what you want; the database decides how to obtain it.
WHY IT IS WORTH LEARNING PROPERLY
Almost every application stores data, and inefficient queries are the commonest performance fault.
WHAT TO LEARN BEYOND BASIC QUERIES
Joins, properly Aggregation and grouping Window functions Indexes, and how queries use them Reading query plans
WHAT CONFIGURATION FORMATS EXIST
Structured data formats used for configuration and interchange.
WHAT TO BE CAREFUL WITH
Formats sensitive to indentation Formats permitting arbitrary object construction, which can execute code Comments, which some formats do not support
WHAT MARKUP AND TEMPLATE LANGUAGES DO
Describe documents and generate output.
WHAT INFRASTRUCTURE DESCRIPTION LANGUAGES DO
Declare desired infrastructure state, applied by tooling.
WHY THAT MATTERS
Infrastructure defined in files is reviewable, versioned and repeatable.
WHAT TO TREAT THEM AS
Code: version controlled, reviewed and tested.
