Ingres 11 Technical Preview

Version 11 of Actian's Ingres open source RDBMS, is going to be a major release as indicated by the jump in the version number. The sequence goes 10.0.0, 10.1.0, 10.2 and from there to 11. This heralds quite a few changes and welcome additions.

The technical preview available at the moment provides only the bare minimum of information, so we dug deeper and can now reveal the most important new features, as far as developers are concerned, broken down by category.

Drivers/Connectivity Version 11 comes bundled with JDBC driver version 4.3 that supports Java8 and above. DAS or Data Access Server , the component that enables connectivity for .NET client application, replaces the JDBC server, as such unifying access of both JDBC and .NET clients under DAS. Network level compression is enabled by default on JDBC and .NET client connections, and can be explicitly disabled by setting the connection attribute "compress=off." The .NET data provider is integrated with VS2015 , while a new utility, ' dotnetinfo ', makes the file version of the .NET Data Provider (Ingres.Client.dll) easily available, a necessity when communicating with Actian's support desk in case of troubleshooting. Diagnostics/Debugging SET SERVER_TRACE, SET SESSION_TRACE replaces trace point sc930. Trace points are low level instructions that force the client or server to emit more information on their internal workings, useful for performance tuning and troubleshooting.

sc930 or Query Tracing, gives the ability to trace all queries processed by the DBMS, capturing them in a textual format that permits their manual replaying, so that you get insight on which queries are run and how they're processed.sc930 is usable with older clients like those constructed with ABF (Applications by Forms, an Ingres propriety 4GL UI/green screen design tool) but wouldn't work with newer client technologies like JDBC, ODBC or .Net.As such the new SET SERVER_TRACE, SET SESSION_TRACE directives unify the tracing functionality for all kind of clients.

SQL enhancements

Hashing functions generate a fixed length, that varies depending on the function used, "hash" value of the data passed in as argument.The following hashing functions find their way into version 11:

MD5SUM(c1) returns the calculated MD5 message digest of its argument (c1) in CHAR(32) format type and length. SHA1SUM(expr) returns the SHA-1 checksum of the input data, in CHAR(40) format type and length. SHA224SUM, SHA256SUM, SHA384SUM and SHA512SUM work in a similar way. CREATE TABLE IF NOT EXISTS brings Ingres up to date with other RDBMSs. AES symmetric encryption for BLOB (binary large object) columns based on an AES key size of 128, 192, 256 bits,(128 by default), and a user provided pass phrase; COMMENT ON [VIEW] The COMMENT ON statement which creates a comment on a table, or column, displayable through issuing the HELP COMMENT statement from an isql terminal monitor, now adds support for View objects as well. BOOLEAN to INTEGER coercions coerces 'true' to 1 and 'false' to 0.
IS NOT DISTINCT FROM operator .

Normally a NULL cannot be compared to any other value, including another null value. This new operator changes the game by allowing comparison operations to treat NULLs as equals while comparing the rest of the values with =.So an expression such as:

WHERE columna IS NOT DISTINCT FROM columnb

evaluates to true if both columna and columnb are equal or both columna and columnb are NULL. The opposite, IS DISTINCT FROM , treats NULL as equals but compares the rest with <>.

Windowing Functions Addition of functions lag() and lead().

Lag or Lead return a scalar column value from a row, before (Lag) or after (Lead) the current row, as such useful for comparing values across multiple rows. For example Lag compares values in the current row with values in a previous row, while LEAD compares values in the current row with values in a following row.

Scalar subquery change in behaviour

In previous releases, the following two forms of syntax were equivalent:

SELECT col1_int, col2_float
FROM session.vps18_gtt2
WHERE col1_int = (SELECT col1_int FROM session.vps18_gtt1
WHERE (col1_int>=11100 AND col1_int<=11115))
ORDER BY col1_int;

and

SELECT col1_int, col2_float
FROM session.vps18_gtt2
WHERE col1_int in (SELECT col1_int FROM session.vps18_gtt1
WHERE (col1_int>=11100 AND col1_int<=11115))
ORDER BY col1_int;

Since the subquery is scalar, it should select only one column and return exactly one row, as such the second form which uses the IN operator should had triggered an exception in case the query returned multiple rows. However in the previous Ingres versions, the IN operator was reworked into having the same effect as 'equals ANY' which short circuits and returns on the first occurrence of a match. In other words IN worked as:

SELECT col1_int, col2_float
FROM session.vps18_gtt2
WHERE col1_int = ANY (SELECT col1_int FROM session.vps18_gtt1
WHERE (col1_int>=11100 AND col1_int<=11115))
ORDER BY col1_int;

This now changes so that in that case, a cardinality violation is fired.

SET FLOAT_FORMAT 'format'

copydb and unloaddb are two utilities with which you can extract table data into text files, so they can subsequently be imported into another platform/OS or another Ingres version.The problem with those utilities is that when unloading and then re-importing floats there can be loss of precision when the float format of the operation is not set at the command line, hence the default n10.3 for float4 and float8 columns is used.The general syntax of the format argument for floating point is:

-fkxM.N

-fis literal and signals a floating point format.

kis the data type selector and can be 4 or 8 for float4 or float8 respectively.

xis the format specifier, and can be one of E, F, G, or N. M is the total field width in characters.

Nis the number of decimal places.

Hence to print float4 values in 9 character field with 2 decimalplaces of precision, the flag would be -f4N9.2 .

Therefore SET FLOAT_FORMAT, as in:

SET FLOAT_FORMAT f4F79.38

allows the session wide format to be followed for all subsequent operations, something that renders the action of specifying it on the command line unnecessary.

String functions

This category has seen the most additions in this release, especially with the enchantments of the SoundEx and Substring functions, as well as a new set of text processing algorithm implementations.So to an already impressive set of algorithms implementationsfrom within SQL including the generation or validation of check digits for the EAN (European Article Number), ISBN (International Standard Book Number), UPC (Universal Product Code), or LUHN and VERHOEFF (used in credit cards and many government identification numbers), the following are also added:

DMETAPHONE(c1) Returns the metaphone code from a varchar string using the double metaphone algorithm. JARO_WINKLER(c1 c2) Calculates the jaro_winkler distance betw