Index

Translation reference to convert INDEX statement to Snowflake

Applies to

• SQL Server

• Azure Synapse Analytics

Currently, Create Index statement is not being converted but it is being parsed. Also, if your source code has Create index statements, these are going to be accounted for in the Assessment Report.

Example of Create Index

SQLServer Input

CREATE INDEX my_index_name ON my_table (column1, column2);

CREATE TABLE table_1(
   date_time DATETIME,
   INDEX ix_PatientBaseEpisodes_Version NONCLUSTERED (VersionStamp)
) ON [PRIMARY]

Snowflake Output

----** SSC-FDM-0021 - CREATE INDEX IS NOT SUPPORTED BY SNOWFLAKE **
--CREATE INDEX my_index_name ON my_table (column1, column2)

CREATE OR REPLACE TABLE table_1 (
  date_time TIMESTAMP_NTZ(3)
--                            ,
--  --** SSC-FDM-0021 - CREATE INDEX IS NOT SUPPORTED BY SNOWFLAKE **
--   INDEX ix_PatientBaseEpisodes_Version NONCLUSTERED (VersionStamp)
)
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "transact",  "convertedOn": "06/06/2025",  "domain": "no-domain-provided" }}'
;

Due to architectural reasons, Snowflake does not support indexes so, SnowConvert will remove all the code related to the creation of indexes. Snowflake automatically creates micro-partitions for every table that help speed up the performance of DML operations, the user does not have to worry about creating or managing these micro-partitions.

Usually, this is enough to have a very good query performance however, there are ways to improve it by creating data clustering keys. Snowflake's official page provides more information about micro-partitions and data clustering.