SQL Tuning for Oracle: Examining the 1st Step in SQL Server

Before you set out fixing something, you need to know precisely what’s causing the problem. Otherwise, your efforts and resources are more likely to be wasted. 

For instance, a doctor cannot prescribe something until they have made a diagnosis, and this is also true for your organization’s database. In this case, the first step towards SQL tuning for Oracle is a detailed health check.

Oracle Performance Tuning Tips: More About SQL Server Health Check 

A health check in SQL Server is a comprehensive, detailed inspection of the database, including its settings, equipment, functioning, soundness, fallback strategy, and additional requirements. It informs your Database Administrator of what’s running fine, helps them pick out the problem-causing entities, and create a plan for strengthening. 

As a database professional, you may find a lot of the results and details in a health check report, but it is also important that the report yield action-oriented information. This, along with some useful Oracle performance tuning tips, should prove useful as it will bring you one step closer to the solution to your SQL Server related issues. 

At the same time, you need to analyze if the reports you are getting are accurate and easy to understand, or not. Preferably, a health check will not only enable you to uncover problems, but it will also help you with guidance on how to fix them.

How a Health Check Helps in Oracle Database Performance Tuning

Here are the various advantages of opting for a health check for your database - 

• Eliminates Unwanted Surprises - A SQL Server database is highly complex, yet it is a crucial part of your business. There are several things that could go wrong at any given time, and simply contemplating this is enough to ensure sleepless nights. With a detailed health check, however, you will know all there is to know about your database, and be better equipped to decide whether your database requires Oracle database performance tuning or not.

• Helps Creates a Decent Strategy - The health check you perform will uncover all the issues that need fixing straightaway as well as those that have more time to be worked upon. Also, it will give you a roadmap that will enable you to make minor adjustments, hasten slower processes that are creating performance related problems, and arrange them into a clear strategy, based on the order of priorities.

• Long-Run Performance - A vital aspect of every health check is a review of present as well as long-term scalability in terms of performance. It helps the DBA comprehend the amount of load the current environment can handle without affecting its performance. 

Additionally, they will know about the scaling requirements, and whether SQL tuning for Oracle is needed, all of which helps them prepare for the organization’s requirements for the long haul.

• Fresh Perspective - Regardless of whether you have an in-house Database Administrator or not, you gain a new perspective that will help you assess your database problems and create simple fixes. 

Although SQL Server database administration requires a lot of study, it also offers multiple approaches for an issue. The job of a DBA is to identify the best way around a difficult situation.

Multiple Clustering Indexes & MySQL SQL Performance Tuning

A clustering index is a different type of index that contains the entire data for the rows. Users gain quicker access to rows through clustered indexes because all of the data is on the page reached through the index search.

For bigger tables, the clustered index decreases the number of disk operations, especially in the case of companies that use the index record to save row data on different pages. If you understand the workings of clustered indexes, you can improve MySQL SQL performance tuning as well, which is why we are discussing them in this blog. 

Improving MySQL SQL Performance Tuning: Understanding How Clustered Indexes Work

A majority of storage engines support a maximum of one clustered index per table. While some do not support them at all, others only enable the primary key to become a clustered index. However, functionality and grammar syntax have evolved throughout these years, so users can enhance MySQL SQL performance tuning with the help of such means.

So, how do clustering keys operate? A clustering index basically stores a copy of the whole row and data is typically clustered with a primary key. Therefore, lookups are not considered in the primary index, since a clustering index covers all the queries. In a way, it is the implementing of a table in a different set up.

Clustering indexes have significantly shorter key lengths which is advantageous in terms of performance - they allow quicker insertions as compared to those in covering indexes. Non-MySQL databases also support the inclusion of monkey columns inside an index by offering syntax accordingly. Clustering indexes can also be thought of as exceptional cases under which every column is combined in the form of a nonkey column. 

Some experts may even point out that extra leaves are only saved in B-tree leaves instead of the internal nodes, but it may be helpful in case the size of the row is bigger than that of the key.

Final Thoughts

A clustering index can easily offer the advantages of covering indexes in a convenient way, apart from improving MySQL SQL performance tuning by their implementation. 

It also provides instant performance benefits that could otherwise be tough or unattainable to gain through simple covering indexes. Some databases can regulate indexes during the process of adding information a degree of parameter quicker than different storage engines. They can also compress data, which further raises the value of clustering keys.

Oracle Database and SQL: Know More about Them

Prior to our discussion about the various functions and features that databases have to offer, we need to understand what they are and why we require them in the first place. This blog is aimed at discussing all these aspects in order to develop a sound understanding of Oracle database and SQL performance tuning in the long run. 

What is the Oracle Database and SQL Required for?

Data on a computer needs to be stored somewhere in order to be accessed whenever it will be needed in the future. From basic information related to the goings-on at a retail store, such as employee information, customer’s purchase history, transaction details, etc., to the employee records at an organization, data can be stored in different formats depending on the nature of the information - letters, digits, audio, video, images, and so on. 

One of the first ideas to occur in terms of data recording is opening up a spreadsheet. However, large amounts of information are much more convenient to store in a way that makes it easier to access any piece of it within a fraction of a second. 

And that way is a database. Moreover, when you have thousands of records to store at a single place, where some of that information may also be sensitive, you need a mode of data storage that is not only safe for private data but also prevents you from entering the exact same information repeatedly (duplication of data). 

A database is a well-organized system of storing your data with a set of rules decided by the user. The rules and structures defining the data are shifted as per the organization’s requirements. For instance, some may need to store a greater amount of data, whereas others may not have a large quantity of data but the amount of information that they have is sensitive and needs protective measures.

These aspects are managed by the database in the background to ensure that the data is completely secure and accessible only to certain individuals with the right credentials. Also, data integrity is established along with reliable means to retrieve said information in a fast, reliable manner. Such a robust way of storing information makes Oracle database and SQL a useful means of storage for business organizations of all sizes, which is also because of its ability to serve several users simultaneously and keeping data safe in case of hardware and technical difficulties that lead to system crashes. 

Oracle Database and SQL: Performance Tuning for DBMS

In larger organizations, it is common to own multiple databases, and a database management system like Oracle database and SQL is one of the best ways to conveniently manage them at the same time. Like databases, one organization can also have more than one DBMS due to their varying features and the organization’s specific requirements in each department. 

The following are some of the different types of Database Management Systems available these days - 

• RDBMS (Relational Database Management System)
• NoSQL Database System
• Object-Oriented Database System
• Network Database System
• Hierarchical Database System

RDBMS like Oracle database and MySQL is the most commonly used ones by organizations at present. They do a lot to improve data operations in an organization but need to be ‘tuned’ from time to time. 

This basically means that their performance can be affected by a few factors which experts knowledgeable in this regard, known as database administrators, are tasked to keep an eye on. SQL performance tuning is easy with the help of tools designed specifically for this task, such as those by Tosska Technologies Limited.

SQL Plan Management Oracle- All Fundamentals You Must Know

While you make any changes in the system parameters or upgrade the Oracle database, you will often notice some highly regressed SQL performance or queries. In such cases, you don’t have to panic because it is quite obvious and happens with many whenever any plan gets changed. But the question is- how will you overcome such a nightmare? Well, it’s not that hard. You can use SQL plan management Oracle. 

SQL Plan Management Oracle- How to Create SQL Plan Baselines

Have you ever experienced performance regressions because of some drastic changes in the execution plan? If so, then we have brought to you a smart solution known as SQL Plan Management (SPM). SQL plan management Oracle is a deterrent mechanism that allows the optimizer to automatically handle execution plans while assuring that the database utilizes only verified and known plans.

The execution plan mainly changes because of several system changes. For instance, you might have changed a few optimizer-related parameters or updated stats for some objects manually or automatically. The more substantial change is the database upgrade. These changes can lead to the generation of new execution plans for many of your SQL statements. While some new plans are improvements, some of them are worse that leads to performance regression.

SQL Plan Management (SPM)

SPM enables database users to manage stable yet optimal performance for a set of SQL statements. Further, it incorporates the positive features of plan stability and adaptability, while simultaneously dodging their shortcomings. SPM has two key objectives:

●Offering performance improvement by gracefully accepting database changes, and

●Preventing performance regressions in the face of any changes in the database system. 

A managed SQL statement has an enabled SPM system. SQL plan management Oracle can be controlled manually either partially or wholly or be configured to work automatically. SPM prevents performance regressions by allowing the detection of plan changes for managed SQL statements. For this purpose, SPM manages, on disk, a plan history that comprises distinct execution plans generated for every maintained SQL statement.

Oracle optimizer’s advanced version, SPM aware optimizer uses, accesses, and manages information stored in a repository called the SMB (SQL Management Base). The plan history lets the SPM aware optimizer to identify whether the produced best-cost plan utilizing the cost-based method is a brand new plan or not. A brand new plan outlines a plan changes that can cause a performance regression.

The SPM aware optimizer doesn’t pick a brand new best-cost plan. Instead, it picks from a set of accepted plans called an SQL plan baseline that represents a subset of the plan history. These accepted plans have been either designated to hold good performance or verified to not cause a performance regression. A brand new plan is combined with the plan history as a non-accepted plan. Later, an SPM utility determines its performance and holds it as an accepted plan if it improves the performance or as a non-accepted plan if it reduces the performance.

The plan performance verification method ascertains both plan adaptability and stability. A SQL plan baseline can be created in several ways-

1.     Using a SQL Tuning Set (STS);

2.     From the cursor cache;

3.     Using a staging table; and

4.     Automatically.

SQL plan baselines from STS

If you are upgrading your Oracle Server, you might have an existing STS containing some or all your SQL statements. This STS might include a plan that works satisfactorily.

SQL Plan Baselines from the Cursor Cache

For any cursor that is present in the cache, SQL plan baselines can be automatically created. This lets you create SQL plan baselines for all every statement whose text is similar to the specified string. Various overloaded variations of such function enable you to filter on other cursor features.

SQL plan baselines using a staging table

If you have SQL plan baselines, you can export them to another system. Firstly, create a staging table and pack the SQL plan baselines you need to export. This will pack all SQL plan baselines for statements that match the certain filter. MY_STGTAB, the staging table is a regular table that you must export to the production system with the use of Datapump Export.

On the production system, for creating the SQL plan baselines, you can now unpack the staging table. You must note that the filter for unpacking the staging table isn’t mandatory, it’s optional. Plus, it may be distinct from the one utilized during packing which implies that various SQL plan baselines can be packed into a staging table and selectively unpack only a subset of them on the target system.

Creating SQL plan baselines automatically

SQL plan baselines can also be created automatically for every statement that is repeatable by setting the parameter optimizer_capture_sql_plan_baselines to TRUE (Note: default is FALSE). For any statement, the first plan captured is accepted automatically and becomes part of the SQL plan baseline. Therefore, you must enable this parameter only when you are certain that the default plans perform well. The automatic plan capture mode can only be used when the previous database version is upgraded to a new one.

By now, we expect that you have understood how SQL plan management oracle can be used to create SQL plan baseline. Also, SPM is one of the best oracle SQL query optimization techniques that avoid performance regression.

Top 5 Best Practices To Improve SQL Database Performance Tuning

Database Tuning refers to a group of activities used for homogenizing and optimizing the performance of a database. Usually, it protrudes with query tuning but describes the design of the database files, configuration of the databases’ environment such as CPU, operating systems, etc., and configuration of the DBMS (Database Management System) application. 

Mainly, the database performance tuning is done to maximize the use of system resources so that application or the system works faster and efficiently as possible. Most systems are designed in a way that they can manage their use of system resources. However, in order to improve their efficiency, there still exists room for improvement which can be done by configuring the database and the DBMS and customizing their settings.

Today, we are going to learn some of the best practices implemented by the DBAs and developers to improve SQL query performance or database performance. Here you go-

Creating Optimized Indexes

Indexing acts as a backbone for any RDBMS (relational database management system). No index directly impacts the functioning of a SELECT statement, while the queries will slow down if you put an excess of indexes. The fields and their order in indexing play a vital role during the database performance tuning. While indexing, the most important information to consider is the number of unique values present in a column of the table. For instance, thousands of first names in a column might maximize specific SELECT statements but it also introduce extra index retrieval time due to the big index pages. Therefore, it’s essential to optimize the index to balance between the two processing times. 

Pre-determine the Expected Growth

Indexes create a negative impact on DML (INSERT, UPDATE, and DELETE) queries. When an index is created, the data for indexed columns gets stored on the disk. When the values in the indexed column are changed or new rows of data are inserted into the table, the database needs to reorganize the data storage to create room for the new rows. The reorganization of data storage can take extra troll on DML queries. However, if you need new rows in any table on a frequent basis, you need to specify the expected growth for an index. Also, the terminology for the predetermined growth varies in every database.

Select Limited Data

The less data you retrieve, the faster the query runs. Instead of filtering on the client, add as much filters you can on the server-end. As a result, less data will be sent on the wire and you will get results much faster. Try to eradicate any computed or obvious columns.

Avoid Foreign Key Constraints

The term is mainly used for ensuring data integrity. But, in turn, it affects the performance of your database. So, if your first priority includes performance, you need to modify the process of database performance tuning. The best example of a database avoiding the foreign key constraints is the system tables containing meta-data information about the user databases. However, it is seen that most users are concerned about data integrity. In such cases, they perform the data integrity process in the application layer and use foreign key only in development or QA environment as an error detection feature. This method will not affect the database performance and the data integrity is also protected. 

No Indexes before Loading Data

Dropping indexes on a table before loading a large quantity of data allows the INSERT statement to run faster. Once the insert is completed, it can be re-indexed. You can use a temporary table to load data when thousands of rows in an online system is being inserted. Also, ensure that this temp table doesn’t contain any index. 

Oracle SQL Query Optimization Techniques and Tools Tosska