/bigtable-basics

Bigtable CLI Data Access

This document provides patterns for reading and writing data in Bigtable using the cbt CLI. This is primarily used for debugging and quick data validation.

Configuring cbt for Data Access

echo project = ${BIGTABLE_PROJECT} > ~/.cbtrc
echo instance = ${BIGTABLE_INSTANCE} >> ~/.cbtrc

Reading Data

Read Single Row (Lookup)

Reads all columns and versions for a specific row.

cbt lookup {table_name} {row_key}

Note: cbt lookup is optimized for point reads and is significantly more efficient than using cbt read with a count or filter for retrieving a single known row.

Read N Rows

Reads the first N rows from the table.

cbt read {table_name} count={n}

Read Range

Reads rows between START_KEY (inclusive) and END_KEY (exclusive).

cbt read {table_name} start={start_key} end={end_key}

Read using SQL

For complex queries and aggregations use SQL via the cbt sql command

cbt sql "SELECT * FROM my_table WHERE _key = 'user#123'"

Row Count (Estimate)

Provides an estimate of the number of rows in the table.

gcloud bigtable instances tables describe {table_id}  --instance={instance_id} --view stats

Note: cbt count {table_name} would do a full table scan.

Writing Data

Write Cell (Set)

Writes a value to a specific cell (row, family, and column).

cbt set {table_name} {row_key} {family}:{column}={value}

Example: cbt set my-table user123 profile:email=user@example.com

Deleting Data

Delete Row

cbt deleterow {table_name} {row_key}