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)
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:
RELY
NO RELY
RELY ENABLE
RELY DISABLE
VALIDATE
NOVALIDATE
These will also be commented out.
The ENABLE constraint state will be completely removed from the output code during the conversion process. In the case of the DISABLE state, it will also be removed concurrently with the NOT NULL constraint.
Oracle
IN -> Oracle_03.sql
CREATE TABLE Table1( col1 INT NOT NULL ENABLE, col2 INT NOT NULL DISABLE, col3 INT NOT NULL RELY);
Snowflake
OUT -> Oracle_03.sql
CREATE OR REPLACE TABLE Table1 ( col1 INT NOT NULL, col2 INT , col3 INT NOT NULL/*** SSC-FDM-OR0006 - CONSTRAINT STATE RELY REMOVED FROM NOT NULL INLINE CONSTRAINT ***/ ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}' ;
2.3. Foreign Key
If there is a table with a NUMBER column with no precision nor scale, and another table with a NUMBER(*,0) column that references to the previously mentioned NUMBER column, we will comment out this foreign key.
CREATE OR REPLACE TABLE "MySchema"."MyTable" ("COL1" NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/, CONSTRAINT "PK" PRIMARY KEY ("COL1") ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}' ;
2.4. Virtual Column
Oracle
IN -> Oracle_05.sql
CREATE TABLE "MySchema"."MyTable"("COL1" NUMBER GENERATED ALWAYS AS (COL1 * COL2) VIRTUAL);
Snowflake
OUT -> Oracle_05.sql
CREATE OR REPLACE TABLE "MySchema"."MyTable" ("COL1" NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/AS (COL1 * COL2) ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}' ;
2.5. Identity Column
For identity columns, a sequence is created and assigned to the column.
Oracle
IN -> Oracle_06.sql
CREATE TABLE "MySchema"."BaseTable"("COL0" NUMBER GENERATED BY DEFAULT ONNULLAS IDENTITY MINVALUE 1 MAXVALUE 9999999999999999999999999999 INCREMENT BY 1 START WITH 621 CACHE 20 NOORDER NOCYCLE NOT NULL ENABLE);
Snowflake
OUT -> Oracle_06.sql
CREATE OR REPLACE SEQUENCE MySchema.BaseTable_COL0 INCREMENT BY 1 START WITH 621COMMENT ='FOR TABLE-COLUMN "MySchema.BaseTable".COL0';CREATE OR REPLACE TABLE "MySchema"."BaseTable" ("COL0" NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/ DEFAULT MySchema.BaseTable_COL0.NEXTVAL NOT NULL)COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}';
2.6. CLOB and BLOB column declaration
Columns declared as CLOB or BLOB will be changed to VARCHAR.
CREATE OR REPLACE TABLE T ( Col1 BINARY, Col5 VARCHAR ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}' ;
2.7. Constraint Name
The constraint name is removed from the code because it is not applicable in Snowflake.
Oracle
IN -> Oracle_08.sql
CREATE TABLE "CustomSchema"."BaseTable"("PROPERTY"VARCHAR2(64) CONSTRAINT "MICROSOFT_NN_PROPERTY" NOT NULL ENABLE );
Snowflake
OUT -> Oracle_08.sql
CREATE OR REPLACE TABLE "CustomSchema"."BaseTable" ("PROPERTY"VARCHAR(64) NOT NULL ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}' ;
2.8. Default columns with times
The columns declared as Date types will be cast to match with the specific date type.
Oracle
IN -> Oracle_09.sql
CREATE TABLE TABLE1("COL1"VARCHAR(50) DEFAULT CURRENT_TIMESTAMP);CREATE TABLE TABLE1( COL0 TIMESTAMP(6) DEFAULT CURRENT_TIMESTAMP, COL1 TIMESTAMP(6) DEFAULT CURRENT_TIME, COL2 TIMESTAMP(6) WITH LOCAL TIMEZONE DEFAULT '1900-01-01 12:00:00', COL3 TIMESTAMP(6) WITH TIME ZONE DEFAULT '1900-01-01 12:00:00', COL4 TIMESTAMP(6) WITHOUT TIME ZONE DEFAULT '1900-01-01 12:00:00', COL5 TIMESTAMP(6) DEFAULT TO_TIMESTAMP('01/01/1900 12:00:00.000000 AM', 'MM/DD/YYYY HH:MI:SS.FF6 AM') );
Snowflake
OUT -> Oracle_09.sql
CREATE OR REPLACE TABLE TABLE1 ("COL1"VARCHAR(50) DEFAULT TO_VARCHAR(CURRENT_TIMESTAMP(), 'YYYY-MM-DD HH:MI:SS') ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}' ;--** SSC-FDM-0019 - SEMANTIC INFORMATION COULD NOT BE LOADED FOR TABLE1. CHECK IF THE NAME IS INVALID OR DUPLICATED. ** CREATE OR REPLACE TABLE TABLE1 ( COL0 TIMESTAMP(6) DEFAULT CURRENT_TIMESTAMP() :: TIMESTAMP(6), COL1 TIMESTAMP(6) DEFAULT CURRENT_TIME() :: TIMESTAMP(6), COL2 TIMESTAMP_LTZ(6) DEFAULT '1900-01-01 12:00:00' :: TIMESTAMP_LTZ(6), COL3 TIMESTAMP_TZ(6) DEFAULT '1900-01-01 12:00:00' :: TIMESTAMP_TZ(6), COL4 TIMESTAMP(6) WITHOUT TIME ZONE DEFAULT '1900-01-01 12:00:00' :: TIMESTAMP(6) WITHOUT TIME ZONE, COL5 TIMESTAMP(6) DEFAULT TO_TIMESTAMP('01/01/1900 12:00:00.000000 AM', 'MM/DD/YYYY HH:MI:SS.FF6 AM') :: TIMESTAMP(6) ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},{"attributes":{"component":"oracle"}}' ;
2.9 Sharing and Memoptimize options
Some options in Oracle are not required in Snowflake. That is the case for the sharing and memoptimize options, they will be removed in the output code.
Oracle
IN -> Oracle_10.sql
CREATE TABLE table1 SHARING = METADATA ( id NUMBER,nameVARCHAR2(50),date DATE, CONSTRAINT pk_table PRIMARY KEY (id) ) MEMOPTIMIZE FOR READ;
Snowflake
OUT -> Oracle_10.sql
CREATE OR REPLACE TABLE table1 ( id NUMBER(38, 18) /*** SSC-FDM-0006 - NUMBER TYPE COLUMN MAY NOT BEHAVE SIMILARLY IN SNOWFLAKE. ***/,nameVARCHAR(50),dateTIMESTAMP/*** SSC-FDM-OR0042 - DATE TYPE COLUMN HAS A DIFFERENT BEHAVIOR IN SNOWFLAKE. ***/, CONSTRAINT pk_table PRIMARY KEY (id) ) COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"oracle"}}' ;
2.10 AS SubQuery
The following properties and clauses are unsupported when creating a table through AS SubQuery in Snowflake.
createtabletable1-- NO DROP NO DELETE HASHING USING sha2_512 VERSION v1 -- blockchain_clause not yet supportedDEFAULT COLLATION somenameON COMMIT DROP DEFINITIONON COMMIT DELETE ROWSCOMPRESSNOLOGGINGASselect*from table1;
Snowflake
OUT -> Oracle_11.sql
CREATE OR REPLACE TABLE table1COMMENT ='{"origin":"sf_sc","name":"snowconvert","version":{"major":1, "minor":0},"attributes":{"component":"oracle"}}'-- NO DROP NO DELETE HASHING USING sha2_512 VERSION v1 -- blockchain_clause not yet supportedASselect*from table1;
Known Issues
Some properties on the tables may be adapted to or commented on because the behavior in Snowflake is different.