The world of computer programming and database management is complex, with many terms and concepts that require specialized knowledge to understand fully. Among these are the NLS parameters, binary collation, and linguistic sorts.
In this article, we will explore these topics in detail, providing readers with an overview of the primary keywords, values, and methods involved.
NLS Parameters
The NLS parameters refer to a set of values that determine how databases handle various localization features. These include settings for date, currency, time, language, and other parameters.
Values can be set at the application, session, and system levels, affecting the behavior of individual programs and running processes. Some of the primary NLS parameters include the following:
- Currency Display – This parameter controls how currencies are displayed within the database, including the currency symbol, decimal delimiter, and thousands separator.
- Day Name Spellings – This parameter controls the spelling of the names of the days of the week, which can vary widely between different languages and regions.
- NLS_SORT – This parameter affects the sorting order of characters within the database.
The NLS_SORT parameter can be set to one of two types, binary collation or linguistic collation.
NLS_SORT and Its Types
The NLS_SORT parameter’s values can have a significant impact on the database’s behavior, affecting how sorting operations are performed and displayed. The parameter can be set to one of the two types mentioned above, binary collation or linguistic collation.
Binary collation refers to the process by which the database sorts characters based solely on their binary representation. This method is generally fast and efficient but doesn’t take into account linguistic or cultural differences.
As such, it may not always be suitable for sorting text in different languages accurately. Linguistic collation, on the other hand, takes into account linguistic and cultural differences, providing a more nuanced and accurate sorting method.
However, it can be slower and more resource-intensive than binary collation. ORDER BY is a common operation that uses the NLS_SORT parameter.
By default, the ORDER BY statement sorts data based on the binary collation. However, you can explicitly specify a linguistic sort by setting NLS_SORT to the appropriate value.
BETWEEN is another database statement that relies on NLS_SORT. Depending on the value of NLS_SORT, BETWEEN may work differently, especially when dealing with strings.
The BETWEEN statement evaluates strings from left to right using binary collation by default, which may not always be the desired behavior.
Binary Collation
Binary collation is the process of sorting characters based solely on their binary representation. This method is useful for sorting data in a database regardless of language or region since it provides a quickly and efficiently performant means of sorting.
Database sessions can have a default collation, which defines how data is sorted when not explicitly stated. Some databases offer different binary collation types, which can be selected depending on the requirements.
However, binary collation is not suitable for linguistic sorts. Sorting text in different languages accurately requires more nuanced methods that take into account cultural and linguistic variations.
Unsuitability for Linguistic Sorts
Linguistic sorts require a more intricate and customized approach than binary collation can provide. That is to say, they take into account the linguistic and cultural differences between various languages, providing a more nuanced and accurate sorting method.
If you attempt to perform a linguistic sort using binary collation, the results may not be accurate, making the operation unsuitable for some languages. For instance, French is a language that requires a linguistic sort due to its diacritical marks.
NLS_COMP is a variable that can be used to specify whether the database should perform a case-insensitive or case-sensitive sort. However, it is not suitable for linguistic sorts.
Conclusion
In conclusion, NLS parameters, binary collation, and linguistic sorts are all essential concepts to consider when working with databases. These parameters and methods affect how data is sorted, displayed, and treated within database systems, influencing the behavior of programs, processes, and applications at all levels.
By understanding these concepts, programmers and database administrators can develop more efficient and accurate database systems, providing richer and more nuanced experiences for end-users.
Linguistic Collation
Sorting operations are a crucial aspect of database management. Accurately sorting database data is one of the most important functions that influence users’ experiences with the system.
One of the methods for sorting text data is called the linguistic sort or linguistic collation. The aim of this method is to correctly order text data regarding its proper linguistic order – providing a more nuanced and accurate sorting method compared to binary collation.
Principles of Linguistic Sort
Linguistic sorting requires a more intricate approach than binary sorting. After all, it takes into account the linguistic and cultural differences between various languages, providing a more nuanced and accurate sorting method.
By using this method, text data is sorted based on letters’ proper linguistic order, rather than based on their binary values. The results obtained from linguistic sorting are more accurate and closer to the desired result.
The collation behavior in linguistic sorting is highly dependent on the selected NLS_SORT parameter. By default, the NLS_SORT parameter for most databases is set to Binary Collation.
To attain the correct collation behavior, it is essential to understand the parameters associated with different types of collations. Types of
Linguistic Collation
There are several types of linguistic collation that can be used for sorting text data.
Some of the most common ones are:
- Monolingual Collation – sorting text data in a single language.
- Multilingual Collation – sorting text data in multiple languages.
- Primary Level Collation – sorting text data strictly based on primary letter differences (letter forms).
- Secondary Level Collation – sorting text data based on accents and diacritical marks.
- Tertiary Level Collation – sorting text data based on secondary differences like case or width.
The collation types mentioned above can be paired with some options like Case-sensitive (_CS), Accent-insensitive (_AI), and Case-insensitive (_CI) to further fine-tune the collation behavior.
Monolingual Collation
Monolingual Collation sorts text data in a single language. The two-step character comparison process is the method used in monolingual collation.
The steps are Major and Minor values. Major values are defined in the NLS_SORT parameter’s primary level collation property, while minor values are defined in the NLS_SORT parameter’s secondary level collation property.
An example of the use of the two-step character comparison method is the GERMAN sort setting for the German language. In the German language, the collation behavior requires that two consecutive uppercase letters that are not otherwise separated by punctuation, diacritics, or whitespace, have a small letter in between them – for example, ADAC, Angst, ZDF.
This specific collation behavior is achieved using the string comparison method, which sorts uppercase before lowercase when comparing two characters or a string with a single character.
Setting NLS_SORT for Monolingual Sorting
To sort database data using monolingual collation, the NLS_SORT parameter needs to be set correctly. For example, to sort text data in the German language, the NLS_SORT parameter needs to be set to German_Germany.1252.
The NLS_SORT parameter can be set at three levels: instance, session, or statement. Setting the NLS_SORT parameter at the instance level means that this parameter applies to all sessions and SQL statements on the instance.
Setting it at the session level implies that it only applies to the current session, and setting it at the statement level implies that it only applies to the current SQL statement. In conclusion, understanding the difference between binary and linguistic sorting, the types of linguistic collation, and the principles of linguistic sorting is a crucial aspect of developing efficient and accurate database systems.
By using the correct sorting procedures and NLS_SORT parameters, database administrators can create a user-friendly experience that accurately sorts text data based on linguistic requirements.
Multilingual Collation
Multilingual Collation, as the name implies, is the process of sorting text data in multiple languages. One of the significant challenges in multilingual sorting is the varying levels of precision required for different languages.
For example, while some languages require sorting based on primary letter differences (letter forms), others require sorting based on secondary differences like accents and diacritical marks.
Levels of Precision
The NLS_SORT parameter enables database administrators to select the level of precision required when sorting text data in different languages. Depending on the requirements, database administrators can select one of the three different levels of precision, namely:
- Primary Level Collation – sorting text data strictly based on primary letter differences (letter forms).
- Secondary Level Collation – sorting text data based on accents and diacritical marks.
- Tertiary Level Collation – sorting text data based on secondary differences like case or width.
Another challenge when sorting text data is special characters, as some languages have special characters that are not present in other languages.
Multilingual Collation takes into account these challenges and provides a more accurate sorting method that correctly orders text data across multiple languages.
Setting NLS_SORT for Multilingual Sorting
To sort text data in a multilingual environment, the NLS_SORT parameter’s value needs to be set correctly. For example, to sort text data in the French language, the NLS_SORT parameter needs to be set to French.
For multilingual sorting, the NLS_SORT parameter can also be paired with the options like Case-insensitive (_CI) and Accent-insensitive (_AI) to further refine the sorting behavior. When using accent-insensitive sorting, diacritical marks have no effect on the sorting order.
The same principle applies to case-insensitive sorting, where uppercase and lowercase letters have the same sorting order.
List Collations
List Collation refers to the process of obtaining a list of valid NLS_SORT parameter values that can be used for sorting text data. It is essential to obtain a list of valid NLS_SORT values, especially when dealing with large database systems with multiple localizations.
To obtain a list of valid NLS_SORT values, database administrators can execute a query that lists all available sort parameters. The query scope can be either at the global or session level, depending on the required output.
In conclusion, sorting text data in a multilingual environment can be a complex and demanding task. Given the varying levels of precision required for each language, it is essential to choose the appropriate NLS_SORT parameter value to obtain accurate sorting results.
Furthermore, the proper understanding of the different levels of precision for different languages is crucial in selecting the appropriate NLS_SORT parameter value. Lastly, having a list of valid NLS_SORT parameter values can be a valuable reference tool when managing large database systems that require multilingual sorting.
By carefully selecting the appropriate sorting method and NLS_SORT parameter value, database administrators can create user-friendly database applications that provide accurate sorting results for multilingual text data. Setting
NLS Parameters
Setting the NLS parameters is a crucial aspect of developing efficient and accurate database systems.
It enables database administrators to control the behavior of database processes and programs, which ultimately affects how data is sorted and displayed. One of the NLS parameters that require proper use is the NLS_SORT parameter used in sorting text data.
Using NLSSORT() to Set NLS_SORT for a Specific Query
The NLSSORT() function is a powerful tool that can be used to set the NLS_SORT parameter for a specific query. The NLSSORT() function enables database administrators to specify the sorting behavior for a specific query, overriding the default settings for the entire database system.
The NLSSORT() function can be used to set the various options for NLS_SORT, including case-insensitivity, accent-insensitivity, and multilingual support. Here is an example using the NLSSORT() function to sort text data in a specific query:
SELECT *
FROM my_table
ORDER BY NLSSORT(data_column, 'NLS_SORT=''FRENCH_AI''');In the example above, the data_column in the my_table table is sorted using the French multilingual collation, with the accent and case-insensitive sorting options using NLSSORT().
Scope of NLSSORT()
The NLSSORT() function only sets the NLS_SORT parameter for a specific SQL statement, which is the query that requested the sort. Therefore, after the query completes, the NLS_SORT parameter setting reverts to its original value.
However, this function provides a flexible and powerful means of specifying the exact sorting behavior required for a specific query. It is essential to note that while the NLSSORT() function is useful for overriding the NLS_SORT parameter setting for a specific query, it can impact overall database performance if used indiscriminately.
As such, database administrators are encouraged to use the function judiciously. In conclusion, the NLSSORT() function is a useful tool for setting the NLS_SORT parameter for a specific query.
It enables database administrators to finely tune the sorting behavior for a specific query, overriding the default settings for the entire database system. However, it is essential to note that this function should be used judiciously and with caution since it can impact overall database performance.
By using the NLSSORT() function for specific queries, database administrators can develop efficient and accurate database systems that provide a user-friendly experience. In conclusion, NLS parameters are essential aspects of database management that affect the behavior of processes and applications.
Binary collation and linguistic sorting are two methods used to sort text data with different levels of precision. Multilingual collation enables sorting text data in multiple languages by adjusting the NLS_SORT parameter to suit different languages’ requirements.
Additionally, using the NLSSORT() function can override the default NLS_SORT parameter values for specific queries. Overall, by understanding these concepts, database administrators can develop efficient and accurate database systems that provide a user-friendly experience.
It is crucial to use the appropriate sorting method and NLS parameters for each language to ensure accurate sorting results.