| This directory contains `spannertest`, an in-memory fake Cloud Spanner. A sibling |
| directory, `spansql`, contains types and parser for the Cloud Spanner SQL dialect. |
| |
| `spansql` is reusable for anything that interacts with Cloud Spanner on a |
| syntactic basis, such as tools for handling Spanner schema (DDL). |
| |
| `spannertest` builds on `spansql` for testing code that uses Cloud Spanner client |
| libraries. |
| |
| Neither of these packages aims to be performant nor exact replicas of the |
| production Cloud Spanner. They are reasonable for building tools, or writing |
| unit or integration tests. Full-scale performance testing or serious workloads |
| should use the production Cloud Spanner instead. |
| |
| See [INTERNALS.md](INTERNALS.md) for an explanation of the implementation. |
| |
| Here's a list of features that are missing or incomplete. It is roughly ordered |
| by ascending esotericism: |
| |
| - expression functions |
| - NUMERIC |
| - JSON |
| - more aggregation functions |
| - SELECT HAVING |
| - more literal types |
| - expressions that return null for generated columns |
| - generated columns referencing other generated columns |
| - checking dependencies on a generated column before deleting a column |
| - expression type casting, coercion |
| - multiple joins |
| - subselects |
| - case insensitivity of table and column names and query aliases |
| - transaction simulation |
| - FOREIGN KEY and CHECK constraints |
| - INSERT DML statements |
| - set operations (UNION, INTERSECT, EXCEPT) |
| - STRUCT types |
| - partition support |
| - conditional expressions |
| - table sampling (implementation) |
