SQL, SPL Enhancements Scott Pickett WW Informix Technical Sales For questions about this presentation contact: [email protected]@us.ibm.com ©

SQL, SPL Enhancements

Scott PickettWW Informix Technical SalesFor questions about this presentation contact: [email protected]

© 2013 IBM Corporation

mailto:[email protected]

Agenda

Intersect, Minus/Except Support for Set Operations Select …. into table 4 GB SPL Case Statement Support in SPL Execute Into Support Trigonometric Functions Multiple Distinct Operators Nulls First/Last Sorting Order Genero

© 2013 IBM Corporation2

IDS 12 - Minus, Plus & Intersect Support


Functionality

Extension to the existing UNION/UNION ALL SET operation.

Same rules of UNION also applies e.g.

Both query block should have exact same number of columns.

Comparable data types.

Projection clause will not have BYTE or TEXT.


Functionality

Order by should be at the end.

Precedence will be from left to right, unless they are grouped using parentheses.

There are existing restrictions for UNION and they will apply to these operators too.


Intersect and Minus/Except

Intersect returns only those rows which are returned by both queries and results will be distinct.

Minus/Except will returns distinct rows from the left query which are not found in the right side query.

All keyword is not available for intersect and minus/except.

NULL friendly, means when comparing NULL to NULL they are considered equal.


Examples

create table t1 (col1 int); insert into t1 values (1); insert into t1 values (2); insert into t1 values (2); insert into t1 values (2); insert into t1 values (3); insert into t1 values (4); insert into t1 values (4); insert into t1 values (NULL); insert into t1 values (NULL); insert into t1 values (NULL);

create table t2 (col1 int); insert into t2 values (1); insert into t2 values (3); insert into t2 values (4); insert into t2 values (4); insert into t2 values (NULL);


Examples (cont’d)

Select * from t1 intersect select * from t2;– Returns NULL, 1,3 and 4

Select * from t1 minus/except select * from t2;– Returns 2


Rewrite

Select col2, col2 from t1 intersect select col1, col2 from t2;

Rewrite:

Select distinct * from (select col1, col2 from t1) t11 where exist (select col1, col2 from (select * from t2) t22 where

t11.col1 = t22.col1 and t11.col2 = t22.col2 );


Minus/Except Rewrite

select col1, col2 from t1 minus select col1, col2 from t2;

select distinct * from (select col1, col2 from t1) t11 where not exists (select * from (select col1, col2 from t2) t22 where t11.col1 = t22.col1 and t11.col2 and t11.col2= t22.col2);


SQL Enhancements – New Join Operators Example

– Two tables are created and loaded with data• Includes some, but not all overlapping values

Notice there are duplicate values in the col1 / col12 columns but not in the col2 / col22 columns


SQL Enhancements – New Join Operators Example (cont.)

– Test the intersect operator

Using a single column, just the common values of both result sets are returned



– Test the intersect operator

Adding the second column to the query returns no rows since the col2/col22 values are unique



– Test the minus operator

Returns the values that only exist in tab_1



– Test the minus operator

Adding the second column returns all tab_1 rows because the col2 / col22 values are unique and none of the combinations exist in tab_1


Questions


SQL Enhancement - SELECT INTO


Overview

You can now create persistent tables in IDS that can be accessed across sessions using the result set of a SELECT statement.

Combines the functionality of CREATE TABLE and INSERT into a single statement.

Supports all the Storage options of CREATE TABLE on IDS.

You can now change the EXTENT SIZE and NEXT SIZE of an existing table without having to unload the table first.

Allows you to create new schema from existing tables and populate it with only a subset of data for testing purposes.

Supported in a Flexible Grid environment.

Functionality supported via two different syntax enhancements:

– SELECT col1, col2 FROM sourcetab INTO newtab;– CREATE TABLE newtab AS SELECT col1, col2 FROM sourcetab;


Syntax – Permanent Tables

|-------------------------- SELECT clause --------------------------------------------

,-- STANDARD----, | |>-------- INTO -------+-----------------------+--- tabname --,-----------------------------------------------------------------------,----| | | | | ‘---- RAW -----------’ ‘---| Storage Options |------| Lock Mode Options |---’


Syntax - CREATE TABLE … AS SELECT…

,-- STANDARD---, | |CREATE --+---------------------+--------- TABLE ------- tab_name ----------------------------------------- | |

‘-------RAW --------’ >---,---------------------------------------------------------,--------,--------------------------------

-------------------------------------------------------,------ | | |

| ‘-- ( --,--column_alias , ---,-- ) ---’ ‘--| Storage Options |----| Lock Mode Options |------’ | | ‘---------------<-----------------’

>-------------- AS --------- SELECT clause --------------------|


Technical Details (1) Display Label (or Column Alias) used in SELECT Clause

would be used as Column Name of newly created table.

All expressions other than simple column expressions must have a display label (or column alias).

Any IDS supported SELECT syntax to create a projection list is valid in the SELECT part of the syntax.

The type of the column in the new table would be the same as the type of the corresponding column in the source table.


Technical Details (2) For a non-trivial expression used in the projection list, the

column type would correspond to the return type of the expression.

Will not inherit any constraints, primary keys, LBAC properties, encryption or any other special properties of the columns that are part of the projection list of the SELECT clause.

Any constraint will need to be introduced with ALTER TABLE.

Cannot be part of a sub-query.


How to Create and Populate a Result Table Assuming “col1” is of type INTEGER, then column “fcol1” of new

table would be of type FLOAT.

select col1::float fcol1, col2 from tab1 into stab1; create table stab1 (fcol1, col2) as select col1::float, col2 from tab1;

The above “create table .. as ..” statement can also be written as:

create table stab1 as select col1::float fcol1, col2 from tab1;


Specify Storage Options for a Result Table (1)

select col1::float fcol1, col2 from tab1

into permtab fragment by expression

fcol1 < 300 in dbs1, fcol1 >=300 in dbs2;

create table permtab (fcol1, col2)fragment by expression

fcol1 < 300 in dbs1, fcol1 >=300 in dbs2

as select col1::float, col2 from tab1;



In the following example the target table “permtab” would be fragmented and split across the dbspaces “dbs1” & “dbs2”

select col1::float fcol1, col2

from tab1 into permtab fragment by expression

fcol1 < 300 in dbs1, fcol1 >=300 in dbs2;

create table permtab (fcol1, col2)fragment by expression

fcol1 < 300 in dbs1, fcol1 >=300 in dbs2

as select col1::float, col2 from tab1;



Change the first Extent Size and/or Next Size of a table that contains data (without unloading data):– Specify the new sizes in SELECT INTO and create a new table.

• SELECT * FROM tab1 INTO newtab1 EXTENT SIZE 32 NEXT SIZE 32;

• OR

• CREATE TABLE newtab1 EXTENT SIZE 32 NEXT SIZE 32 AS SELECT * FROM tab1;

– Use ALTER TABLE to introduce any constraints/primary keys.– Create required index on the new table.– Drop index on old table.– Drop old table (“tab1”).– Rename new table (“newtab1”) to same name as old table (“tab1”).– Rename index on new table to the same as for old table.


Questions


4GB Stored Procedure Language Statements


Overview

The maximum length of SQL statements and SPL routines is now 4 GB– The actual limit may depend on the available memory on the system.

Valid for Client SDK 3.70.xC5, JDBC 3.70.xC5 or higher.

Perhaps writing SQL or SPL possibly so large should be avoided for programmer maintenance issues …..


Limitations

Transient extended types, collection types are limited to 65535

sysadmin task command length is limited to 2048


Questions


Case Statement in SPL


Case Usage Overview

In a stored procedure when one needs to take a different branch of execution based on the value of an expression or value of a SPL variable.

Reduces the migration work to be done during conversion from other database products that support CASE statements in stored procedure language.

It can simply programming by replacing multiple IF-ELSE IF statement blocks with a CASE statement in SPL routines.


Technical Details

Syntax diagram for CASE statement in SPL

>>-CASE--value_expr---------------------------------------------> (1) >--+-ELSE--| Statement Block

|--------------------------------------------------------------------------------------+--> | .------------------------------------------------------------------------------

| | V (1) |

| '---WHEN--constant_expr--THEN--| Statement Block |------+--+------------------------------------

+----' | (1) | '-ELSE--| Stmt Block |-------'

>--END CASE---------------------------------------------------------------------><


CASE Statement Execution in SPL

The database server evaluates the value_expr parameter

– If the resulting value matches a literal value specified in the constant_expr parameter of a WHEN clause, the database server executes the statement block that follows the THEN keyword in that WHEN clause.

– If the value of the value_expr parameter matches the constant_expr parameter in more than one WHEN clause, the database server executes the statement block that follows the THEN keyword in the first matching WHEN clause in the CASE statement.

After the database server executes the statement block that follows the THEN keyword, it executes the statement that follows the CASE statement in the SPL routine.


Technical Details (cont’d)

If the value of the value_expr parameter does not match the literal value specified in the constant_expr parameter of any WHEN clause, and if the CASE statement includes an ELSE clause, the database server executes the statement block that follows the ELSE keyword.

If the value of the value_expr parameter does not match the literal value specified in the constant_expr parameter of any WHEN clause, and if the CASE statement does not include an ELSE clause, then the database server returns an error with a message indicating that the specified case not defined in the CASE statement.


How to Use the CASE Statement in SPL

CASE statement without else clause CASE mod(r,314) WHEN 1 THEN select tabid into r from informix.systables where tabid = 1; WHEN 313 THEN LET r = r + 4; WHEN 3 THEN LET r = r + 3;END CASE;

CASE statement with else clause

CASE r WHEN 317 THEN select tabid into r from informix.systables where tabid = 1; WHEN 312 THEN LET r = r + 4; WHEN 3 THEN LET r = r + 3; ELSE LET r = 1;END CASE;


How to use CASE statement (cont’d)

CASE statement with boolean value and null value

CASE state WHEN 't' THEN LET grade = 'a'; WHEN 'f' THEN LET grade = 'b'; WHEN NULL THEN LET grade = 'c'; ELSE LET grade = 'd'; END CASE;

CASE statement with multi-statement block

CASE r WHEN 6 THEN BEGIN select 4 into r from informix.systables where tabid = 1; LET r = r - 1; END WHEN 4 THEN LET r = r + 4; END CASE;


Questions


execute into Statement


execute into Informix has increased the support for, and usability of, UDRs and

the values they return– Informix has supported execute procedure

• For UDRs that do not return a value

– as well as execute function• For UDRS that do return value(s)

When calling a UDR, input and potential return values are defined with the in, out and/or inout keywords


execute into Informix 12.10 functions that return a value can now directly

populate a program variable with the execute into syntax– The variable has to be defined and initialized before the function is called

Example

execute function scale_rectangles( rectid = 107, scale = 1.9 ) into new_rectang


Questions


Mathematical Functions


New Mathematical Functions – Oracle Compatibility

SIGN(num)– Returns the sign of the input numeric value (returns integer):

• -1 for n < 0, 0 for n = 0, and 1 for n > 0 COSH(num)

– Returns hyperbolic cosine (returns float) SINH(num)

– Returns hyperbolic sine (returns float) TANH(num)

– Returns hyperbolic tangent (returns float) ACOSH(num)

– Returns arc hyperbolic cosine (returns float) ASINH(num)

– Returns arc hyperbolic sine (returns float) ATANH(num)

– Returns arc hyperbolic tangent (returns float) LN(num)

– Alias for existing LOGN(num) function (returns float)


Multiple Distinct Operators


Multiple distinct Operators Example

– Legal syntax• Applied to each predicate

– Illegal syntax • Nested operators

select avg(unique col1), count (distinct col2) from my_tab;

select distinct avg(distinct col1) from my_tab;


Questions


Nulls First/Last Sorting Order


SQL Enhancements – nulls first / last When selecting and ordering a column that contains nulls, whether

the data is sorted in ascending or descending order affects where the null values appear– Ascending puts the nulls first– Descending puts the nulls last

The nulls first / nulls last keywords can be used to move the nulls to the top or bottom of the result regardless of the sort order


SQL Enhancements – nulls first / last Example

Default null sort order with the asc keyword

Modified null sort order with the asc nulls last keywords


SQL Enhancements – nulls first / last Example

Default null sort order with the desc keyword

Modified null sort order with the desc nulls first keywords


SQL Enhancements – Windows XML Enhancement

The XML4C and XSLT4C libraries have been ported to Windows 64 enabling XML functionality on that port.


Questions


Genero 2.41 - Enhancements


IBM Informix Genero v2.41

eGA’ed in December, 2012

Genero Application Server and Genero Web Client– HTML5 snippets and CSF (aka javascript) update – Enhanced support for Genero features

Feature enhancements worth taking a note– The Layout– Store Settings and Table Columns UI – Traditional mode (to ease migration from i4GL) – TTY attributes and Genero 4ST – Modal windows and Popup menus – Picture flow

• Better touch based (tablets and phones) ergonomics • Android4 compatibility • iOS5 (iPad and iPhone) compatibility • Hybrid Application templates for iOS and Android


IBM Informix Genero v2.41

Enhancements to Genero Studio– BAM has new templates– Provide additional modeling options to define the functionality provided

by each form, such as add/modify/delete.– Data access code and constraints will be centralized at the database

meta-schema level.– Operations on forms will be published as Web services to provide a

high level access on data by program

Defect fixes for all components– GWS, FGL, GDC, GRV, GAS, GWC, GST, GRE


2013 IIUG Informix ConferenceApril 21 – 25, 2013

San Diego Marriott Mission Valley - San Diego, California, USA

The Board of Directors of the International Informix Users Group (IIUG) announces the IIUG 2013 Informix Conference, to be held at the San Diego Marriott Mission Valley on April 21 - 25, 2013.

Early Bird registration only $750(USD) until January 17, 2013. All paid attendees receive Thursday tutorials included!

For more details visit the official conference web site www.iiug2013.org© 2013 IBM Corporation70

http://www.iiug2013.org/

http://www.marriott.com/hotels/travel/sanmv-san-diego-marriott-mission-valley/

http://www.iiug2013.org/

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SQL, SPL Enhancements Scott Pickett WW Informix Technical Sales For questions about this presentation contact: [email protected]@us.ibm.com ©