# Data Preparation ### Joining different datasets by a common column

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example demonstrates how to use Workflows to join two tables based on a common ID on both tables. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/join.sql)

### Join two datasets and group by a property

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example shows how to use Workflows to join two tables together and then group by a specific property, producing aggregated data coming from both sources. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/join_and_group_by.sql)

### Union of two data sources with same schema

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example demonstrates how to use Workflows to generate a table that contains all the rows from two different sources with the same schema. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/union.sql)

### Filter rows using a custom geography

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example demonstrates how to use Workflows to filter a data source using a custom geography input. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/custom_geo_filter.sql)

### Generate a calculated column from a multi-column formula

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example demonstrates how to use Workflows to generate a new column using a formula that involves different columns in the calculation. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/multi-column_formula.sql)

### Normalize a variable to an index between 0 and 1

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example demonstrates how to use Workflows to obtain a normalized index from a column in your dataset. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/normalize.sql)

### Rank and limit a table

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example demonstrates how to use Workflows to sort a table by a specific property, and only keep a certain number of rows. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/rank_and_limit.sql)

### Filter columns

CARTO DW	BigQuery	Snowflake	Redshift	PostgreSQL	Snowflake	Redshift	PostgreSQL	CARTO DW
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This example demonstrates how to use Workflows to reduce a dataset to a smaller number of columns required for a specific analysis.. [**Download example**](https://storage.googleapis.com/carto-workflows-examples/files/filter_columns.sql)