-
Notifications
You must be signed in to change notification settings - Fork 4
Add baseline infrastructure for emulating materialized views #56
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Draft
amotl
wants to merge
1
commit into
main
Choose a base branch
from
materialized
base: main
Could not load branches
Branch not found: {{ refName }}
Loading
Could not load tags
Nothing to show
Loading
Are you sure you want to change the base?
Some commits from the old base branch may be removed from the timeline,
and old review comments may become outdated.
Draft
Changes from all commits
Commits
File filter
Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Empty file.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,65 @@ | ||
# Copyright (c) 2023-2025, Crate.io Inc. | ||
# Distributed under the terms of the AGPLv3 license, see LICENSE. | ||
import logging | ||
|
||
import sqlalchemy as sa | ||
|
||
from cratedb_toolkit.materialized.model import MaterializedViewSettings | ||
from cratedb_toolkit.materialized.store import MaterializedViewStore | ||
from cratedb_toolkit.model import TableAddress | ||
|
||
logger = logging.getLogger(__name__) | ||
|
||
|
||
class MaterializedViewManager: | ||
""" | ||
The main application, implementing basic synthetic materialized views. | ||
""" | ||
|
||
def __init__(self, settings: MaterializedViewSettings): | ||
# Runtime context settings. | ||
self.settings = settings | ||
|
||
# Materialized store API. | ||
self.store = MaterializedViewStore(settings=self.settings) | ||
|
||
def refresh(self, name: str): | ||
""" | ||
Resolve a materialized view and refresh it. | ||
""" | ||
logger.info(f"Refreshing materialized view: {name}") | ||
|
||
table_address = TableAddress.from_string(name) | ||
mview = self.store.get_by_table(table_address) | ||
logger.info(f"Loaded materialized view definition: {mview}") | ||
|
||
sql_ddl = f"DROP TABLE IF EXISTS {mview.staging_table_fullname}" | ||
logger.info(f"Dropping materialized view (staging): {sql_ddl}") | ||
self.store.execute(sa.text(sql_ddl)) | ||
|
||
sql_ddl = f"CREATE TABLE IF NOT EXISTS {mview.staging_table_fullname} AS (\n{mview.sql}\n)" | ||
logger.info(f"Creating materialized view (staging): {sql_ddl}") | ||
self.store.execute(sa.text(sql_ddl)) | ||
sql_refresh = f"REFRESH TABLE {mview.staging_table_fullname}" | ||
self.store.execute(sa.text(sql_refresh)) | ||
|
||
sql_ddl = f"CREATE TABLE IF NOT EXISTS {mview.table_fullname} (dummy INT)" | ||
logger.info(f"Creating materialized view (live): {sql_ddl}") | ||
self.store.execute(sa.text(sql_ddl)) | ||
amotl marked this conversation as resolved.
Show resolved
Hide resolved
|
||
|
||
# TODO: Use `ALTER TABLE ... RENAME TO ...` after resolving issue. | ||
# SQLParseException[Target table name must not include a schema] | ||
# https://github.com/crate/crate/issues/14833 | ||
# CrateDB does not support renaming to a different schema, thus the target | ||
# table identifier must not include a schema. This is an artificial limitation. | ||
# Technically, it can be done. | ||
# https://github.com/crate/crate/blob/5.3.3/server/src/main/java/io/crate/analyze/AlterTableAnalyzer.java#L97-L102 | ||
sql_ddl = f"ALTER CLUSTER SWAP TABLE {mview.staging_table_fullname} TO {mview.table_fullname}" | ||
logger.info(f"Activating materialized view: {sql_ddl}") | ||
self.store.execute(sa.text(sql_ddl)) | ||
sql_refresh = f"REFRESH TABLE {mview.table_fullname}" | ||
self.store.execute(sa.text(sql_refresh)) | ||
|
||
sql_ddl = f"DROP TABLE IF EXISTS {mview.staging_table_fullname}" | ||
logger.info(f"Dropping materialized view (staging): {sql_ddl}") | ||
self.store.execute(sa.text(sql_ddl)) | ||
amotl marked this conversation as resolved.
Show resolved
Hide resolved
|
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,98 @@ | ||
# Copyright (c) 2023, Crate.io Inc. | ||
# Distributed under the terms of the AGPLv3 license, see LICENSE. | ||
import dataclasses | ||
import os | ||
import typing as t | ||
|
||
from sqlalchemy_cratedb.support import quote_relation_name | ||
|
||
from cratedb_toolkit.model import DatabaseAddress, TableAddress | ||
|
||
|
||
@dataclasses.dataclass | ||
class MaterializedView: | ||
""" | ||
Manage the database representation of a "materialized view" entity. | ||
|
||
This layout has to be synchronized with the corresponding table definition | ||
per SQL DDL statement within `schema.sql`. | ||
""" | ||
|
||
table_schema: t.Optional[str] = dataclasses.field( | ||
default=None, | ||
metadata={"help": "The target table schema"}, | ||
) | ||
table_name: t.Optional[str] = dataclasses.field( | ||
default=None, | ||
metadata={"help": "The target table name"}, | ||
) | ||
sql: t.Optional[str] = dataclasses.field( | ||
default=None, | ||
metadata={"help": "The SQL statement defining the emulated materialized view"}, | ||
) | ||
|
||
id: t.Optional[str] = dataclasses.field( # noqa: A003 | ||
default=None, | ||
metadata={"help": "The materialized view identifier"}, | ||
) | ||
|
||
@property | ||
def table_fullname(self) -> str: | ||
return quote_relation_name(f"{self.table_schema}.{self.table_name}") | ||
|
||
@property | ||
def staging_table_fullname(self) -> str: | ||
return quote_relation_name(f"{self.table_schema}-staging.{self.table_name}") | ||
|
||
@classmethod | ||
def from_record(cls, record) -> "MaterializedView": | ||
return cls(**record) | ||
|
||
def to_storage_dict(self, identifier: t.Optional[str] = None) -> t.Dict[str, str]: | ||
""" | ||
Return representation suitable for storing into a database table using SQLAlchemy. | ||
|
||
Args: | ||
identifier: If provided, this will override any existing id in the instance. | ||
""" | ||
|
||
# Serialize to dictionary. | ||
data = dataclasses.asdict(self) | ||
|
||
# Optionally add identifier. | ||
if identifier is not None: | ||
# Explicitly override any existing id. | ||
data["id"] = identifier | ||
|
||
return data | ||
|
||
|
||
def default_table_address(): | ||
""" | ||
The default address of the materialized view management table. | ||
""" | ||
schema = os.environ.get("CRATEDB_EXT_SCHEMA", "ext") | ||
return TableAddress(schema=schema, table="materialized_view") | ||
|
||
|
||
@dataclasses.dataclass | ||
class MaterializedViewSettings: | ||
""" | ||
Bundle all configuration and runtime settings. | ||
""" | ||
|
||
# Database connection URI. | ||
database: DatabaseAddress = dataclasses.field( | ||
default_factory=lambda: DatabaseAddress.from_string("crate://localhost/") | ||
) | ||
|
||
# The address of the materialized view table. | ||
materialized_table: TableAddress = dataclasses.field(default_factory=default_table_address) | ||
|
||
# Only pretend to invoke statements. | ||
dry_run: t.Optional[bool] = False | ||
|
||
def to_dict(self): | ||
data = dataclasses.asdict(self) | ||
data["materialized_table"] = self.materialized_table | ||
return data |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,30 @@ | ||
# Materialized Views Baseline Infrastructure | ||
|
||
## About | ||
|
||
This subsystem provides a foundation for emulating materialized views in CrateDB. | ||
It addresses the need to optimize query performance by caching the results of | ||
complex or resource-intensive SQL queries in regular tables that can be refreshed | ||
on a scheduled basis. | ||
|
||
The subsystem emulates materialized views so that queries that take a long | ||
time to run can be cached, which is specifically useful when applied in | ||
scenarios with high traffic in reads. This approach can significantly reduce | ||
the database load and improve response times for frequently accessed data. | ||
|
||
## Features | ||
|
||
- Create and manage materialized view definitions | ||
- Refresh materialized views on demand or on schedule | ||
- Track metadata about materialized views for management purposes | ||
- Support for different refresh strategies | ||
|
||
## Prior Art | ||
|
||
- https://github.com/nroi/elfenbein | ||
- https://github.com/nroi/pg_materialized_views_refresh_topologically | ||
- https://github.com/darkside/monocle | ||
- https://github.com/maggregor/maggregor | ||
- https://github.com/adamfoneil/ViewMaterializer | ||
- https://github.com/jhollinger/activerecord-viewmatic | ||
- https://github.com/q-m/metabase-matview |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,36 @@ | ||
# Copyright (c) 2021-2025, Crate.io Inc. | ||
# Distributed under the terms of the AGPLv3 license, see LICENSE. | ||
import logging | ||
from importlib.resources import read_text | ||
|
||
from cratedb_toolkit.materialized.model import MaterializedViewSettings | ||
from cratedb_toolkit.util.database import run_sql | ||
|
||
logger = logging.getLogger(__name__) | ||
|
||
|
||
def setup_schema(settings: MaterializedViewSettings): | ||
""" | ||
Set up the materialized view management table schema. | ||
|
||
TODO: Refactor to `store` module. | ||
""" | ||
|
||
logger.info( | ||
f"Installing materialized view management table at " | ||
f"database '{settings.database.safe}', table {settings.materialized_table}" | ||
) | ||
amotl marked this conversation as resolved.
Show resolved
Hide resolved
|
||
|
||
# Read SQL DDL statement. | ||
sql = read_text("cratedb_toolkit.materialized", "schema.sql") | ||
|
||
tplvars = settings.to_dict() | ||
sql = sql.format_map(tplvars) | ||
amotl marked this conversation as resolved.
Show resolved
Hide resolved
|
||
|
||
if settings.dry_run: | ||
logger.info(f"Pretending to execute SQL statement:\n{sql}") | ||
return | ||
|
||
# Materialize table schema. | ||
run_sql(settings.database.dburi, sql) | ||
run_sql(settings.database.dburi, f"REFRESH TABLE {settings.materialized_table.fullname}") | ||
amotl marked this conversation as resolved.
Show resolved
Hide resolved
|
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,13 @@ | ||
-- Set up the materialized view management database table schema. | ||
CREATE TABLE IF NOT EXISTS {materialized_table.fullname} ( | ||
|
||
"id" TEXT NOT NULL PRIMARY KEY, | ||
|
||
-- Target: The database table to be populated. | ||
"table_schema" TEXT, -- The source table schema. | ||
"table_name" TEXT, -- The source table name. | ||
|
||
-- The SQL statement defining the emulated materialized view. | ||
"sql" TEXT | ||
|
||
); |
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Uh oh!
There was an error while loading. Please reload this page.