oracle sql tuning books

1 exp Tuning 1.1 Use direct and recordlength options The direct parameter defines whether to use direct path (direct = y) or conventional path (direct = n) for export ). Conventional path export uses the SQL SELECT statement to extract data from the table. direct path export reads data directly from the disk to the PGA and writes the data to the export file as is, this avoids the data conversion process

statement, which, through the Awrsqrpt.sql script, can generate information such as the execution plan of the specified SQL (once executed SQL), the resources consumed, and so on, to help DBAs with SQL tuning. Here's how to do this first, or execute the build script: sql> @

Do you want to learn some tips for tuning SQL PL? If this is the case, this article will describe some common examples of tuning ibm®db2®universal database™ (UDB) V8.2 for linux,unix®, and Windows®, and will pay special attention to porting from other database management systems Come over the process. Motivation SQL p

and normal operation. Follow-up articles are described in turn.About the use of this piece of hint, the content is quite a lot of, some of which also contains lock hints, etc., follow-up articles we introduced in turn, interested children shoes in advance attention.In fact, hint is an important tool when we tune up. However, the correct use of this tool relies on solid fundamentals and accumulated experience.The so-called: thick accumulated thin hair ! Do not easily see the use of the scene to

An analysis of tuning "session management Overhead"IntroductionDuring tuning, the management of sessions is a common problem because the overhead of maintaining sessions is relatively high."The process behaves as follows"Client request (SID) → Listener received → listener derived new process (systemprocess ID) → Client processComments:Spid:system process ID, which represents the process ID of the serverproc

to select the crosstab (intersection table) as the underlying table, which is the table referenced by the other table.Like what: The EMP table description describes the intersection of the location table and the category table. SELECT * FROM location L, CATEGORY C, EMP E WHERE e.emp_no between, and e.cat_no = C.cat _no and e.locn = L.LOCNwill be more efficient than the following SQL: SELECT * from EMP E, location L, CATEGORY

reassigned, where each thread is assigned an average of 25 rows of data In this case, the results we are going to get are all divided into 4 threads, each thread is assigned 25 rows of data, and the next step is to give the nested loop connection, because we need to get the data rows from BigTable2 in the above statement, so we have chosen a nested loop, Scan BigTable2 to get the data in turn. For Nested loop join operators, you can refer to my second article. We know that this is the number

Label:ObjectiveIn the previous article, we analyzed how the query optimizer works, including: detailed operation steps of the query optimizer, analysis of filter conditions, optimization of index items, and other information.In this article we analyze the detection of several key indicator values in the course of our operation.These indicator values are analyzed to analyze the operation of the statement and to analyze how it is optimized.Through this article we can learn the

Read Catalogue Objective Technical preparation ObjectiveIn the previous article, we analyzed how the query optimizer works, including: detailed operation steps of the query optimizer, analysis of filter conditions, optimization of index items, and other information.In this article we analyze the detection of several key indicator values in the course of our operation.These indicator values are analyzed to analyze the operation of the statement and to analyze how it is optimized

-------------------------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU) | Time |-------------------------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | 11 | 189 (1) | 00:00:03 || 1 | RESULT CACHE | 27yjysxpdun18b2utun82bynny | | | | || 2 | SORT AGGREGATE | | 1 | 11 | | ||* 3 | INDEX RANGE scan| idx$$_003600

Note: This article source: Small yan Kevin "Oracle Database Memory adjustment increased memory "Simulated operating system memory increased from 2G to 8G, adjust the database memory parameters, the example parameter is not as the actual production environment reference, because the need to take, adjust the parameters need to adjust according to the database, to avoid the calf pull cart, Daniel pull the car phenomenon.View RAW configuration Data1[Email

first wait event is read by other session. Top 5 Timed Foreground Events Read by other session is defined as follows: Read by other session Definition: When information is requested from the database, Oracle will first read the data from disk into the database buffer cache. if two or more sessions request the same information, the first session will read the data into the buffer cache while other sessions wait. in previous versions this wait was clas

of data ... God horse is not as good as Oracle ...!!!There are some children's shoes simply think that SQL Server is pediatrics, there is no technical content ... It's very simple.On these points, I don't want to spit out anything, I just want to let those friends who really know SQL Server to prove something to SQL S

As mentioned in parts 1th and 2nd, there are several relatively easy steps to improve performance you can take, one of these steps involves using an automated tool to "guide" you to write SQL statements, there are many production performance analysis or performance tuning tool manufacturers, in the following article, We will examine one of them. Quest Software Many DBAs and developers use a tool called To

One of the practical skills that can greatly improve the performance of SQL TUNING optimization. When we perform SQL optimization, we often encounter the need to sort a large number of datasets and then retrieve the first part of the results from the sorted set. In this case, when we write SQL statements according to t

fromV$thread T, V$parameter vWHEREV.name= 'Thread' and(V.value= 0 ORt.thread#=To_number (v.value))) I, (SELECTVALUE fromV$parameterWHERENAME= 'user_dump_dest') D;3.2 Using the Tkprof command to beautify the generated trace fileHere is what I often use, for more detailed instructions on the tkprof command, you can see the tkprof command directly enter.Tkprof xxx.trc xxx.txt Explain=system/Oracle sys=nReference URL: http://www.eygle

ConclusionThis article first to this bar, short, easy to understand, this article mainly introduces the query plan of the joint operators, the next we analyze SQL Server parallel operations, in multicore hyper-threading gathered today, see SQL How server uses parallel operations to maximize the use of existing hardware resources to improve performance, is interested in advance attention, the content o

large print segments18.count (*) is slightly faster than count (1), of course, if you can retrieve by index, the count of indexed columns is still the fastest. 19. Replace the HAVING clause with a WHERE clause to avoid having a HAVING clause, having The result set is filtered only after all records have been retrieved19. Avoid using like ' * ' to avoid using is null or20.Note:A, programmers pay attention to the amount of data in each table.B, the coding process and the unit test process as far

Tags: des style blog http color using strong AR dataBackgroundMySQL and Oracle were used before, and there was not much use for SQL Server. Recently, due to project reasons, to read the database of other projects, take out a gate of the switch history, and the other side of the use of SQL Server, so the study of SQL Se

future space to introduce, interested can advance attention.Reference documents Microsoft Books Online Read page Refer to the book SQL. server.2005. Technical Insider "series If you have any questions, you can leave a message or private messages, and look forward to an in-depth study of your child's shoes with SQL Server. Learn together and pro