Class: ActiveRecord::ConnectionAdapters::VirgodbAdapter

Inherits:
SQLite3Adapter
  • Object
show all
Defined in:
lib/activerecord-virgodb-adapter.rb

Overview

ActiveRecord adapter for virgodb migrations -- lets any Rails app define and evolve a virgodb table's schema the same way it already does for SQLite (bin/rails db:migrate) and ClickHouse (the clickhouse-activerecord gem): real ActiveRecord::Migration subclasses, raw type strings, picked up by rails db:migrate alongside every other database.

virgodb's manifest is already a real SQLite file, so subclassing SQLite3Adapter (not building from AbstractAdapter) gets structure_dump/structure_load -- the :sql schema format -- for free, zero custom dumper code. Only create_table/add_column need overriding: call super for a real, if never-written-to, SQLite table (SQLite's type-name grammar accepts arbitrary bare-word type declarations -- verified against a real connection, see crates/compact/src/schema.rs's doc comment for the exact grammar and why it has to be "AnyLast String updated_at", not "AnyLast(String, updated_at)"), and additionally record the column in a schema_versions table matching exactly what compact::schema_from_columns on the Rust side expects to parse.

One manifest can back several virgodb tables sharing a single database.yml connection and migrations path -- the same way a host app's clickhouse: connection might already hold all of its ClickHouse tables under one connection. schema_versions (and the Rust-side manifest's run_files/inline_batches/orphaned_files/ maintenance_lease catalog tables) are scoped by table_name specifically to make this safe: each logical table's schema history and physical run files stay independent even though they live in the same SQLite file.

Additive-only, matching Manifest::register_schema_version's own rule and virgodb's immutable-Parquet philosophy: remove_column, rename_column, and change_column are all disabled outright rather than silently letting the real SQLite table drift out of sync with what schema_versions describes.

Constant Summary collapse

ADAPTER_NAME = 
"Virgodb"

Instance Method Summary collapse

Instance Method Details

#add_column(table_name, column_name, type, **options) ⇒ Object 



80
81
82
83
84
 
# File 'lib/activerecord-virgodb-adapter.rb', line 80

def add_column(table_name, column_name, type, **options)
  result = super
  record_added_column!(table_name, column_name, type, options)
  result
end

#change_column(table_name, column_name, type, **options) ⇒ Object

Raises:

  • (NotImplementedError) 


94
95
96
 
# File 'lib/activerecord-virgodb-adapter.rb', line 94

def change_column(table_name, column_name, type, **options)
  raise NotImplementedError, "virgodb schemas are additive-only -- an existing column's type can't change"
end

#configure_connection ⇒ Object

Real bug, found (not assumed) by testing: setting auto_vacuum = INCREMENTAL from create_table -- even from create_table's very FIRST call on a brand-new manifest, before any table exists -- was already too late. SQLite3Adapter's own configure_connection sets journal_mode = wal via DEFAULT_PRAGMAS (super, below) as part of establishing the connection itself, which happens before this adapter's create_table ever runs -- and switching journal_mode to WAL requires SQLite to actually write to the file (creating the -wal file, an implicit checkpoint), which "poisons" the database from auto_vacuum's perspective the same way any other content would. Confirmed directly: a manual PRAGMA auto_vacuum = INCREMENTAL issued immediately after establish_connection, before ANY table or migration ran, still silently failed. The pragma has to be set before super runs here, not merely before the first CREATE TABLE.



69
70
71
72
 
# File 'lib/activerecord-virgodb-adapter.rb', line 69

def configure_connection
  @raw_connection.auto_vacuum = "incremental" if @raw_connection.respond_to?(:auto_vacuum=)
  super
end

#create_table(table_name, **options, &block) ⇒ Object 



74
75
76
77
78
 
# File 'lib/activerecord-virgodb-adapter.rb', line 74

def create_table(table_name, **options, &block)
  result = super
  record_schema_version!(table_name)
  result
end

#remove_column(table_name, column_name, type = nil, **options) ⇒ Object

Raises:

  • (NotImplementedError) 


86
87
88
 
# File 'lib/activerecord-virgodb-adapter.rb', line 86

def remove_column(table_name, column_name, type = nil, **options)
  raise NotImplementedError, "virgodb schemas are additive-only -- columns can be added, never removed (see schema_versions)"
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object

Raises:

  • (NotImplementedError) 


90
91
92
 
# File 'lib/activerecord-virgodb-adapter.rb', line 90

def rename_column(table_name, column_name, new_column_name)
  raise NotImplementedError, "virgodb schemas are additive-only -- columns can't be renamed once created"
end