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If you find an error or have a suggestion for improving our content, we would appreciate your feedback. So have you tried looping through or you may have to test to see what works at a time? This can reduce a lot of contention on the table and make things work faster.
If you have enterprise manager database control you can use the performance tools to see what is causing the delay. My guess is that is has something to do with IO performance of the redo logs OR as others mentioned a locking issue. But the problem should be locks , you can check for locks with Killing an oracle session to remove a lock script.
Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 10 years ago. Active 6 years, 10 months ago. Viewed 27k times. Is there any enhancement I can do to increase the performance.
I tried to add index on archive but with no effect. Improve this question. Jeffrey Kevin Pry 3, 3 3 gold badges 34 34 silver badges 67 67 bronze badges.
This seems crazy it would take 3 hours even if you didn't index anything at all. Do you have a primary key defined? However, if set too high, then the memory paging that occurs will cripple indexing speed. With parallel indexing, each stream requires its own index memory. When dealing with very large tables, you can tune your database system global area SGA differently for indexing and retrieval.
For querying, you are hoping to get as much information cached in the system global area's SGA block buffer cache as possible. So you should be allocating a large amount of memory to the block buffer cache.
But this will not make any difference to indexing, so you would be better off reducing the size of the SGA to make more room for a large index memory settings during indexing. Oracle Text Reference to learn more about Oracle Text system parameters. Generally, the larger the total amount of text, the smaller the overhead, but many small records will use more overhead than fewer large records.
Also, clean data such as published text will require less overhead than dirty data such as emails or discussion notes, since the dirty data is likely to include many unique words from mis-spellings and abbreviations. A text-only index is smaller than a combined text and theme index. A prefix and substring index makes the index significantly larger. Answer: You can expect much lower storage overhead for formatted documents such as Microsoft Word files since such documents tend to be very large compared to the actual text held in them.
So 1GB of Word documents might only require 50MB of index space, whereas 1GB of plain text might require MB, since there is ten times as much plain text in the latter set. Indexing time is less clear-cut. Although the reduction in the amount of text to be indexed will have an obvious effect, you must balance this out against the cost of filtering the documents with the INSO filter or other user-defined filters.
Answer: Parallel indexing can improve index performance when you have a large amount of data, and have multiple CPUs. This will create the index with up to three separate indexing processes depending on your resources. Parallel indexing can also be used to create local partitioned indexes on partitioned tables.
However, indexing performance only improves when you have multiple CPUs. Parallel querying degrades query throughput especially on heavily loaded systems. Because of this, Oracle recommends that you disable parallel querying after parallel indexing. Answer: When you have multiple CPUs, you can improve indexing performance by creating a local index in parallel.
There are two ways to index in parallel:. In this case, the maximum parallel degree is limited to the number of partitions you have. This method can result in a higher degree of parallelism, especially if you have more CPUs than partitions. The following is an example for the second method. In this example, the base table has three partitions. Also inside each partition, index creation is done in parallel intra-partition parallelism with a parallel degree of 2.
This section answers some of the frequently asked questions about updating your index and related performance issues. However, this means that your data will become progressively more out of date, which may be unacceptable for your users.
Many systems are OK with overnight indexing. This means data that is less than a day old is not searchable. Other systems use hourly, ten minute, or five minute updates. Answer: The best way is to time some queries, run index optimization, then time the same queries restarting the database to clear the SGA each time, of course. If the queries speed up significantly, then optimization was worthwhile. If they don't, you can wait longer next time.
Answer: Yes, the same way as for normal indexing. But of course, there are often far fewer records to be indexed during a synchronize operation, so it is not usually necessary to provide hundreds of megabytes of indexing memory. Note: As this hint is cost-based, Oracle recommends that you collect statistics on your tables before you use this hint.
See "Collecting Statistics " in this chapter. When you need the entire result set, do not use this hint as it might result in poor performance. Traces are cumulative counters, so usage is as follows: The user enables a trace.
Question and Answer. Hi Tom, Yeah you are right john as the index will take more time in the update statement. Since i am using the same column in where condition, i have created the indexes. I tested the above update statement with and without indexes and the observation is it is taking more time when it doesn't have any index. Please provide me any solution for this.
Thanks in advance.
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