postgresql performance comparison

First, the use of explain: PostgreSQL generates a query plan for each query because the performance impact of selecting the correct query path is critical. PostgreSQL itself already contains a planner for finding the optimal plan, and we can view the query plan generated by the planner for each query by using the explain command.The query plan generated in

t.taxno like CONCAT ('% ',? , '% ') Sql server:Select t.* from Sj_receiptinfo T WHERE t.taxno like '% 'PostgreSQL: SELECT *. (T. Category Code | | '-' | | T. Invoice number) as number from the account where username ~* ' Baidu ';Find information about all user names in the data table account, including Baidu and those that do not distinguish between uppercase and lowercase 4. Infer nullOracle: SELECT productname,unitprice* (unitsinstock+NVL(unit

PostgreSQL Performance Optimization considerations caused by connection to IPVs that consumes cpu resources in particular. bitsCN.com Because it is in the development stage, the postgres parameter is not configured, and the default configuration during installation is used,In the past, nothing was abnormal, but my cpu usage suddenly increased a few days ago.Check the process and find that the CPU usage of o

To increase the persuasion, each operation can be set to repeat the number of repetitions, the greater the average result is more convincing. Here, 1 or 10 is set according to the situation (see the comment of the main function). There is time for students to set up a larger number.Paste Results First:The contrast is: add (); AddLast (); Get (); Remove () method.Results Analysis:Add method: The contrast performance is more obvious: the insertion time

PostgreSQL supports hstore to store data such as Key->value, which is in fact similar to array or JSON type. Efficient indexing is essential to the efficient use of this type of data. Let's take a look at the performance issues of two different types of indexes for the same retrieval request today.If we had such an original table. There is a Btree index based on the Str1 field.t_girl=# \d Status_check;

statements to reduce the cost of committing a transaction;Use cluster when extracting multiple records from an index;Use limit when extracting part of a record from a query result;Use pre-compiled queries (Prepared query);Use analyze to maintain accurate optimization statistics;Regular use of VACUUM or pg_autovacuumDelete indexes first when making large amounts of data changes (then rebuilding indexes)2, program ExperienceCheck the program, whether the use of connection pool, if not used, as so

PostgreSQL provides some functions to help improve performance. There are several main aspects. 1. Use the explain command to view the execution plan. In the previous blog PostgreSQL provides some functions to help improve performance. There are several main aspects. 1. Run the EXPLAIN command to view the execution pla

Comparison of Grid control performance and wpfgrid performance on the WPF Platform The first official version of WPF has been released for 10 years, and we have almost started the development of XAML at the same time. Even after years of building, we still try to improve: Have we really created efficient and flexible controls? I have not found any introduction to

. Net Core memory recovery mode and performance test comparison and analysis, core comparison and analysis . NET Core two GC modes: Server GC/Workstation GC Server GC: It is mainly used in multi-processor systems and serves as the default configuration of the ASP. NET Core host. It creates a GC Heap for each processor and executes the recycle operation in paralle

To the photographic enthusiasts for detailed analysis to share the Canon IXUS140 camera performance and Canon 60D camera performance comparison. Analytical sharing: Canon IXUS140 employs a 16 million-pixel 1/2.3-inch CCD image sensor, equipped with a DIGIC 4 image processor, and an ISO range iso100-iso1600. and Canon 60D with a valid pixel of 18 million

1. Use EXPLAIN:PostgreSQL generates a query plan for each query, because selecting the correct query path has a critical impact on performance. PostgreSQL itself contains a scheduler for optimal planning. We can use the EXPLAIN command to view the scheduler's query plan generated for each query.The query plan generated by PostgreSQL is a planning tree consisting

To the photographic enthusiasts for detailed analysis to share the Canon A4000 is camera performance and Canon 60D camera performance comparison. Analytical sharing: Canon A4000 is a 1/2.3 inch CCD sensor, with 16 million active pixels, equipped with DIGIC 4 Image processor, to make portrait shooting better. and Canon 60D with a valid pixel of 18 mi

To the photographic enthusiasts to share a detailed analysis of Canon IXUS155 performance and Canon 60D performance comparison. Compare and share: Canon IXUS155 is equipped with a 20 million megapixel 1/2.3 inch CCD sensor, is the first camera in the canon to reach 20 million pixels, but also broke the only Sony using the 20 million pixel level sensor m

To the photographic enthusiasts for detailed analysis to share the Canon A4000 is camera performance and Nikon D5200 camera performance comparison. The comparison is detailed: Canon A4000 is equipped with a 3.0-inch 230,000-pixel LCD LCD screen, using the material of engineering plastics, the display effect i

Give the photographer a detailed analysis of the performance of the Canon 6D camera and the performance comparison of the Nikon D600 camera. Analytical sharing: Canon 6D is equipped with the DIGIC 5+ Digital imaging processor, which achieves a maximum of about 4.5/second high-speed burst, and also has a 11-point autofocus system with a F2.8-pr

To the photographic enthusiasts for detailed analysis to share the Canon G16 camera performance and Canon 7D camera performance comparison. Analytical sharing: On the sensor side Canon G16 is still 1/1.7 inch 12.1 million effective pixel CMOS image sensor, up to ISO 12800, combined with DIGIC 6 digital imaging processor, to achieve 12.2/second

Give the photographer a detailed analysis to share the performance of the Canon G1X camera and the performance comparison of the Nikon D7100 camera. Analytical sharing: Canon G1X lens using 4 times times three optical zoom lens, equivalent 28-112mm, aperture range of f2.5-16, and the recent focus distance of 20 cm (wide angle end), 85 cm (long

To the photographic enthusiasts for detailed analysis to share the performance of Canon SX510 HS and Canon 7D performance comparison. Analytical sharing: Canon SX510 HS uses 1/2.3 inch, effective pixel 12 million of the back-camera CMOS image sensor, the sensitivity range of iso100-iso6400, compared to SX500 HS can use a higher sensitivity ISO

To the photographic enthusiasts for detailed analysis to share the Canon IXUS140 camera performance and Canon 7D camera performance comparison. Compare and share: Canon IXUS140 has 8 times times optical zoom lens, focal length is equivalent to 35mm 28-224mm, set up intelligent automatic shooting mode, can at any time for the image to be photographed intellig