![]() ![]() If there is any violation between the constraint and the data action,Ĭonstraints can be column level or table level. ThisĮnsures the accuracy and reliability of the data in the table. SQL constraints are used to specify rules for the data in a table.Ĭonstraints are used to limit the type of data that can go into a table. There are some aspects of Transact-SQL stored procedures that aren't implemented in dedicated SQL pool, which are as follows:įor more development tips, see development overview.String Functions: ASCII CHAR_LENGTH CHARACTER_LENGTH CONCAT CONCAT_WS FIELD FIND_IN_SET FORMAT INSERT INSTR LCASE LEFT LENGTH LOCATE LOWER LPAD LTRIM MID POSITION REPEAT REPLACE REVERSE RIGHT RPAD RTRIM SPACE STRCMP SUBSTR SUBSTRING SUBSTRING_INDEX TRIM UCASE UPPER Numeric Functions: ABS ACOS ASIN ATAN ATAN2 AVG CEIL CEILING COS COT COUNT DEGREES DIV EXP FLOOR GREATEST LEAST LN LOG LOG10 LOG2 MAX MIN MOD PI POW POWER RADIANS RAND ROUND SIGN SIN SQRT SUM TAN TRUNCATE Date Functions: ADDDATE ADDTIME CURDATE CURRENT_DATE CURRENT_TIME CURRENT_TIMESTAMP CURTIME DATE DATEDIFF DATE_ADD DATE_FORMAT DATE_SUB DAY DAYNAME DAYOFMONTH DAYOFWEEK DAYOFYEAR EXTRACT FROM_DAYS HOUR LAST_DAY LOCALTIME LOCALTIMESTAMP MAKEDATE MAKETIME MICROSECOND MINUTE MONTH MONTHNAME NOW PERIOD_ADD PERIOD_DIFF QUARTER SECOND SEC_TO_TIME STR_TO_DATE SUBDATE SUBTIME SYSDATE TIME TIME_FORMAT TIME_TO_SEC TIMEDIFF TIMESTAMP TO_DAYS WEEK WEEKDAY WEEKOFYEAR YEAR YEARWEEK Advanced Functions: BIN BINARY CASE CAST COALESCE CONNECTION_ID CONV CONVERT CURRENT_USER DATABASE IF IFNULL ISNULL LAST_INSERT_ID NULLIF SESSION_USER SYSTEM_USER USER VERSION SQL Server Functions For an example, see the article on temporary tables. There is, however, an alternative approach you can use. INSERT.EXECUTEĭedicated SQL pool doesn't permit you to consume the result set of a stored procedure with an INSERT statement. But, if you do, you need to rework your code to fit the nesting levels within this limit. It's unlikely that you'll exceed the eight nest level limit. CREATE PROCEDURE prc_nesting_2ĮXEC sp_executesql 'SELECT 'another nest level' - This call is nest level 2ĭedicated SQL pool doesn't currently support As such, you need to track the nest level. If the second procedure then executes some dynamic SQL, the nest level increases to three. CREATE PROCEDURE prc_nestingĮXEC prc_nesting_2 - This call is nest level 2 If the stored procedure also makes another EXEC call, the nest level increases to two. The top-level stored procedure call equates to nest level 1. In contrast, the nest level in SQL Server is 32. ![]() When stored procedures call other stored procedures, or execute dynamic SQL, then the inner stored procedure or code invocation is said to be nested.ĭedicated SQL pool supports a maximum of eight nesting levels. The SQL code that is executed against the data is different than the query submitted. During this process, each statement is converted into distributed queries. When a dedicated SQL pool executes your stored procedure, the SQL statements are parsed, translated, and optimized at run time. So, it's helpful to think of stored procedures as containers for SQL logic. The goal is to save hours, minutes, and seconds, not milliseconds. It's more important to ensure the stored procedure code is correctly optimized for large queries. In general, for data warehouses, the compilation time is small in comparison to the time it takes to run queries against large data volumes. The biggest difference compared to SQL Server is that the stored procedure isn't pre-compiled code. ![]() Each stored procedure can also accept parameters to make them even more flexible.ĭedicated SQL pool provides a simplified and streamlined stored procedure implementation. Stored procedures also help developers modularize their solutions by encapsulating the code into manageable units, thus facilitating greater code reusability. Stored procedures are a great way for encapsulating your SQL code, which is stored close to your dedicated SQL pool data. More importantly, there are scale-out specific features that you can use to maximize the performance of your solution.Īlso, to help you maintain the scale and performance of dedicated SQL pool, there are additional features and functionalities that have behavioral differences. What to expectĭedicated SQL pool supports many of the T-SQL features that are used in SQL Server. This article provides tips for developing dedicated SQL pool solutions by implementing stored procedures.
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