ExtSort

Short Description

ExtSort sorts input records according to a sort key.

COMPONENT	SAME INPUT METADATA	SORTED INPUTS	INPUTS	OUTPUTS	JAVA	CTL	AUTO-PROPAGATED METADATA
ExtSort	-	x	1	1-N	-	-	✓

Ports

PORT TYPE	NUMBER	REQUIRED	DESCRIPTION	METADATA
Input	0	✓	For input data records	the same input and output metadata
Output	0	✓	For sorted data records	the same input and output metadata
	1-N	x	For sorted data records	the same input and output metadata

This component has one input port and at least one output port.
If more output ports are connected, ExtSort sends each record to all connected output ports.

Metadata

Metadata can be propagated through this component. All output metadata must be same as the input metadata. ExtSort does not change metadata.

ExtSort Attributes

ATTRIBUTE	REQ	DESCRIPTION	POSSIBLE VALUES
BASIC
Sort key	✓	Key according to which the records are sorted. For more information, see Sort Key.	name(a);age(d)
ADVANCED
Buffer capacity		The maximum number of records parsed in memory. If there are more input records than this number, external sorting is performed.	8000 (default) \| 1-N
Number of tapes		The number of temporary files used to perform external sorting. Even number higher than 2.	6 (default) \| 2*(1-N)
DEPRECATED
Sort order		Order of sorting (`Ascending` or `Descending`). Can be denoted by the first letter (`A` or `D`) only. Same for all key fields.	Ascending (default) \| Descending
Sorting locale		Locale that should be used for sorting.	none (default) \| any locale
Case sensitive		In the default setting of Case sensitive (`true`), upper-case and lower-case characters are sorted as distinct characters. Lower-cases precede corresponding upper-cases. If Case sensitive is set to `false`, upper-case characters and lower-case characters are sorted as if they were identical. The Case sensitive attribute value is taken into account only if Locale is set.	true (default) \| false
Sorter initial capacity		it does the same as Buffer capacity.	8000 (default) \| 1-N

Details

ExtSort receives data records through the single input port, sorts them according to a specified sort key and copies each of them to all connected output ports.

The Sort key is defined by one or more input fields and the sorting order (ascending or descending) for each field. The resulting sequence also depends on the key field type: string fields are sorted in ASCIIbetical order while other fields are sorted alphabetically.

Sorting Null Values

In ascending order, null values are sorted before strings, numbers, booleans or dates. If you sort data in descending order, null values are sorted after strings, numbers, booleans or dates.
Remember that ExtSort processes records in which the same fields of the Sort key attribute have null values as if these nulls were equal.

Examples

Sorting according to a single field

This example shows the basic usage of ExtSort.
Input records contains file names and their size. Sort the files according to their size starting with the biggest one.
Input records

file.txt  |    2048
file.docx | 1048576
file.xml  |   65536

Solution
In ExSort, set Sort key attribute: drag the field name from the left list to the right one and change Order to Descending.

ATTRIBUTE	VALUE
Sort key	FileSize(d)

The result would be:

file.docx | 1048576
file.xml  |   65536
file.txt  |    2048

Sorting according to multiple fields

This example shows sorting values according to a multiple-part key.
Each record contains first name, last name and year of birth. Sort the records according to all three fields. Sort the records according to last name and first name in ascending order. If there are more records with the same first and last name, the youngest one should be the first.

Jane | Doe | 1843
John | Doe | 1798
John | Doe | 1859

Solution
Set the Sort key attribute. In the dialog to define the key. The first part of the key (last name) should be on the top of the list on the right side. The first name should be the second and the year of birth should be the last one.

ATTRIBUTE	VALUE
Sort key	Surname(a);FirstName(a);YearOfBirth(d)

The result would be:

Jane | Doe | 1843
John | Doe | 1859
John | Doe | 1798

Sorting with locale

This example shows sorting records with locale.
Input records contains a list of French words. Sort the words according to the French collation.

parler
être
aller

Solution
In ExtSort, set Sort key and Sorting locale attributes.

ATTRIBUTE	VALUE
Sort key	Word(a);
Sorting locale	fr.FR

The result will be:

aller
être
parler

Without the proper sorting locale, the result would be aller, parler, être.