Create Table

In this section you could find information about TABLES, their syntax and current convertions.

1. Description

In Oracle, the CREATE TABLE statement is used to create one of the following types of tables: a relational table which is the basic structure to hold user data, or an object table which is a table that uses an object type for a column definition. (Oracle documentation)

Oracle syntax

CREATE [ { GLOBAL | PRIVATE } TEMPORARY | SHARDED | DUPLICATED | [ IMMUTABLE ] BLOCKCHAIN 
  | IMMUTABLE  ] 
   TABLE
  [ schema. ] table
  [ SHARING = { METADATA | DATA | EXTENDED DATA | NONE } ]
  { relational_table | object_table | XMLType_table }
  [ MEMOPTIMIZE FOR READ ]
  [ MEMOPTIMIZE FOR WRITE ]
  [ PARENT [ schema. ] table ] ;

Snowflake Syntax

CREATE [ OR REPLACE ]
    [ { [ { LOCAL | GLOBAL } ] TEMP | TEMPORARY | VOLATILE | TRANSIENT } ]
  TABLE [ IF NOT EXISTS ] <table_name> (
    -- Column definition
    <col_name> <col_type>
      [ inlineConstraint ]
      [ NOT NULL ]
      [ COLLATE '<collation_specification>' ]
      [
        {
          DEFAULT <expr>
          | { AUTOINCREMENT | IDENTITY }
            [
              {
                ( <start_num> , <step_num> )
                | START <num> INCREMENT <num>
              }
            ]
            [ { ORDER | NOORDER } ]
        }
      ]
      [ [ WITH ] MASKING POLICY <policy_name> [ USING ( <col_name> , <cond_col1> , ... ) ] ]
      [ [ WITH ] TAG ( <tag_name> = '<tag_value>' [ , <tag_name> = '<tag_value>' , ... ] ) ]
      [ COMMENT '<string_literal>' ]

    -- Additional column definitions
    [ , <col_name> <col_type> [ ... ] ]

    -- Out-of-line constraints
    [ , outoflineConstraint [ ... ] ]
  )
  [ CLUSTER BY ( <expr> [ , <expr> , ... ] ) ]
  [ ENABLE_SCHEMA_EVOLUTION = { TRUE | FALSE } ]
  [ STAGE_FILE_FORMAT = (
     { FORMAT_NAME = '<file_format_name>'
       | TYPE = { CSV | JSON | AVRO | ORC | PARQUET | XML } [ formatTypeOptions ]
     } ) ]
  [ STAGE_COPY_OPTIONS = ( copyOptions ) ]
  [ DATA_RETENTION_TIME_IN_DAYS = <integer> ]
  [ MAX_DATA_EXTENSION_TIME_IN_DAYS = <integer> ]
  [ CHANGE_TRACKING = { TRUE | FALSE } ]
  [ DEFAULT_DDL_COLLATION = '<collation_specification>' ]
  [ COPY GRANTS ]
  [ COMMENT = '<string_literal>' ]
  [ [ WITH ] ROW ACCESS POLICY <policy_name> ON ( <col_name> [ , <col_name> ... ] ) ]
  [ [ WITH ] TAG ( <tag_name> = '<tag_value>' [ , <tag_name> = '<tag_value>' , ... ] ) ]

For more Snowflake information review the following documentation.

2. Sample Source Patterns

2.1. Physical and Table Properties

Oracle

IN -> Oracle_01.sql
CREATE TABLE "MySchema"."BaseTable"
(
    BaseId NUMBER DEFAULT 10 NOT NULL ENABLE
) SEGMENT CREATION IMMEDIATE
  PCTFREE 0 PCTUSED 40 INITRANS 1 MAXTRANS 255
  COLUMN STORE COMPRESS FOR QUERY HIGH NO ROW LEVEL LOCKING LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1
  BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "MyTableSpace"
  PARTITION BY LIST ("BaseId")
 (
    PARTITION "P20211231"  VALUES (20211231) SEGMENT CREATION DEFERRED
    PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255
    ROW STORE COMPRESS ADVANCED LOGGING
    STORAGE(
    BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
    TABLESPACE "MyTableSpace" 
  )
  PARALLEL;

Snowflake

OUT -> Oracle_01.sql
CREATE OR REPLACE TABLE "MySchema"."BaseTable"
 (
     BaseId NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/ DEFAULT 10 NOT NULL
 )
 COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}'
 ;

Table properties are removed because they are not required after the migration in Snowflake.

2.2. Constraints and Constraint States

The following constraints will be commented out:

  • CHECK Constraint

The USING INDEX constraint will be entirely removed from the output code during the conversion.

Oracle

IN -> Oracle_02.sql
CREATE TABLE "MySchema"."BaseTable"
(
    BaseId NUMBER DEFAULT 10 NOT NULL ENABLE NOVALIDATE,
    "COL1" NUMBER CHECK( "COL1" IS NOT NULL ),
	  CHECK( "COL1" IS NOT NULL ),
    CONSTRAINT "Constraint1BaseTable" PRIMARY KEY (BaseId)
        USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS
        STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
        PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1) ENABLE
);

Snowflake

OUT -> Oracle_02.sql
CREATE OR REPLACE TABLE "MySchema"."BaseTable"
	(
	    BaseId NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/ DEFAULT 10 NOT NULL,
	    "COL1" NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/ NOT NULL
 	                                                                                                                     !!!RESOLVE EWI!!! /*** SSC-EWI-0035 - CHECK STATEMENT NOT SUPPORTED ***/!!!
 	                                                                                                                     CHECK( "COL1" IS NOT NULL ),
	!!!RESOLVE EWI!!! /*** SSC-EWI-0035 - CHECK STATEMENT NOT SUPPORTED ***/!!!
		  CHECK( "COL1" IS NOT NULL ),
	    CONSTRAINT "Constraint1BaseTable" PRIMARY KEY (BaseId)
	)
	COMMENT = '{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"oracle"}}'
	;

On the other hand, but in the same way, in case you have any constraint state after a NOT NULL constraint as follows: