Conventions

Shell commands and SQL statements are shown in separate code blocks. Run shell commands in a terminal; enter SQL in the database client. The prompts are omitted so that they do not become part of copied commands.

SQL keywords are written in uppercase and example identifiers in lowercase. A semicolon ends a statement. Quoted text values such as 'Alice' are data, not identifiers. SQL NULL denotes a missing value, not an empty string.

Examples and Results

The English and Russian editions use the same identifiers, fixture data and executable SQL files. Explanations are translated; commands are not. Result tables show the expected values rather than terminal border characters. An explicit ORDER BY is used where row order matters.

Shell variables such as tutorial_dir must remain available for the exercise. Do not substitute a production database path into a tutorial command. A database used by one exercise is not a backup of another database.

Versions and Limits

The heading identifies the documentation target. Build details distinguish that target from the application manifest and the source revision. An explicit limitation means the supported 1.2 behavior is narrower than the surrounding feature; behavior described only in a plan is not part of the user contract.

Limits are qualified as implementation limits, configuration limits or measured workload sizes. Measurements are not universal capacity guarantees.