Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Appearance settings

docs: set index_cols in read_gbq as a best practice #624

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.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We鈥檒l occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Apr 22, 2024
Merged

docs: set index_cols in read_gbq as a best practice #624

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
0ddd86b
docs: set `index_cols` in `read_gbq` as a best practice
tswast Apr 19, 2024
b96cba3
document behaviors
tswast Apr 22, 2024
3d70f76
Merge branch 'main' into b335727141-docs
tswast Apr 22, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 11 additions & 7 deletions 18 third_party/bigframes_vendored/pandas/io/gbq.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,13 +27,17 @@ def read_gbq(
):
"""Loads a DataFrame from BigQuery.

BigQuery tables are an unordered, unindexed data source. By default,
the DataFrame will have an arbitrary index and ordering.

Set the `index_col` argument to one or more columns to choose an
index. The resulting DataFrame is sorted by the index columns. For the
best performance, ensure the index columns don't contain duplicate
values.
BigQuery tables are an unordered, unindexed data source. To add support
pandas-compatibility, the following indexing options are supported:

* (Default behavior) Add an arbitrary sequential index and ordering
using an an analytic windowed operation that prevents filtering
push down.
* (Recommended) Set the ``index_col`` argument to one or more columns.
Unique values for the row labels are recommended. Duplicate labels
are possible, but note that joins on a non-unique index can duplicate
rows and operations like ``cumsum()`` that window across a non-unique
index can have some non-deternimism.

.. note::
By default, even SQL query inputs with an ORDER BY clause create a
Expand Down
Morty Proxy This is a proxified and sanitized view of the page, visit original site.