How oracle will come to know weather it is recovery of Instance or Media Recovery

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• How I can scan the registry valuHi, how I can scan the Windows 7 registry value and how do I come to know if the registry value is same as it has been installed previously?

  Hello

  How can I scan the Windows 7 registry value and how do I come to know if the registry value is same as it has been installed previously?

  Hello
   
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  Windows registry Description of the audit of the Windows Registry tool (Scanreg.exe) How do I add, edit or delete subkeys in registry and values by using a registration entries (.reg) file Hope this information helps

   
   
   

• How oracle will show the large amount of data

  Hi all

  I have server Oracle 11 g on linux os 2. Total sga size is 500 MB only. Now, if customs wants to read the 1 GB of data from database, there no sufficient memory in the buffer cache. So how it will work. the transaction will get successful or it will fail.

  And I have another doubt, done oracle can read data from memory only or it can also read directly on the disc.

  Please let know us your opinion. Thank you.

  Please go through the below documents

  Oracle library documentation

  asktom:how Database Buffer Cache works?

  Oracle database concepts

• Hello! I bought an i phone 6s in Latvia at a store like euronics, but I will come back to Italy and I would like to know if I'll be able to use it... Thank you very much

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• I signed up for CC. I don't know that this Dreamweaver will come into conflict with my older version of CS5. You can run two versions of the DW on a single computer?

  I signed up for CC. I don't know that this Dreamweaver will come into conflict with my older version of CS5. You can run two versions of the DW on a single computer?

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• How Oracle process concurrent requests

  Hi all
  
  Database: 11g
  
  I'm trying to understand how an Oracle DB handles multiple (simultaneous) requests submitted at the same time? One of my colleagues said that it can process only one instance at a time and not really treat multpile queries at a time. Is this true? An insertion point doesn't seem right to me, but I couldn't find any information on how he manages in fact several requests at once.
  
  Any info, etc. would be greatly appreciated.
  
  Thank you
  
  S

  >
  I'm trying to understand how an Oracle DB handles multiple (simultaneous) requests submitted at the same time? One of my colleagues said that it can process only one instance at a time and not really treat multpile queries at a time. Is this true? An insertion point doesn't seem right to me, but I couldn't find any information on how he manages in fact several requests at once.

  Any info, etc. would be greatly appreciated.
  >

  In contrast to some databases (they also have changed the behavior now), Oracle has never locks the table for read operations. First, Oracle have always pick up blocks at the moment (compatible mode) for a query and current mode for an LMD. When a session is a select statement, Oracle will read the segment headers and go and get the blocks. Like all queries are made in compatible mode, no matter how many sessions is but they all do the same becomes coherent. If some of these blocks have been changed until the query has begun but not committed or rolled back, Oracle will know that they are back and go and get them. But they are also in the buffer. Now, while the session is ended to retrieve the blocks (while still working Session 2), it would be possible that some session DML has updated some blocks that Session2 would have to pick up. Now 2 Session should also rebuild the undo blocks for blocks of the pre-image. It's why you can see while the meeting has made 1000 becomes coherent, is it possible that Session2 should be 5000 gets consistent because it was to read UNDO blocks so.

  To extend the subject on works the Oracle query mechanism, if the blocks are in the buffer cache, it will bring (LIO) and send it back to the PGA TOUR that he will send back to the client in the form of data. If blocks are not in the cache, it will go and read disks (PIO) and before to return data to the PGA, stop and load the buffer cache and then send it back to PGA and then back to the client. So now when Session B comes in next with the same query, Oracle will get from the buffer and return it immediately.

  You want to do a trace on sessions 1 and 2 for example (all by doing an update the same table Session 3 prior to the session 2 finishes) and you will see clearly how Oracle worked for your query.

• My new hard drive (from HP) will come with windows?

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  Hello:

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• How long will it take? Installation of Win 7 USB

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  PLUG
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• Oracle will produce Certification Exam preparation seminar for ECAS 12 c Perf Tuning, Rac, Data Guard?

  Hello

  Oracle will produce Certification Exam preparation seminar for Oracle 12 c OCÉ Perf Tuning, Rac, Data Guard?

  I took the seminar for RAC and oracle 11 GRID infrastructure certification exam.

  I was wondering if they will ever do this course of preparation for Oracle 12 c for

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  Thank you Roger

  I don't know if everything is still planned for the creation of the seminars review for these exams. If/when they are released, they will be announced on our blog - blogs.oracle.com/certification.

  Kind regards
  Brandye Barrington

  Oracle Certification program

• How much will be / * + PARALLEL * / use?

  Hello

  I've always used / * + PARALLEL (tablename, degree) * / but I recently saw a query using just / * + PARALLEL * /.

  How much will be / * + PARALLEL * /. use? the degree with which the table is created? If Yes, what happens if the table is created without any parallelism.

  I tried to search the Internet but no conclusive answer, so approaching again the expert forum is not found.

  I've always used / * + PARALLEL (tablename, degree) * / but I recently saw a query using just / * + PARALLEL * /.

  How much will be / * + PARALLEL * /. use? the degree with which the table is created? If Yes, what happens if the table is created without any parallelism.

  I tried to search the Internet but no conclusive answer, so approaching again the expert forum is not found.

  Interesting - I searched using "parallel index of oracle 11 g" and this was the FIRST link

  http://docs.Oracle.com/CD/E11882_01/server.112/e25523/parallel002.htm

  Then I searched the page for "parallel" and find section 19.1.2.7 tips for parallel execution which was State

  You can specify the parallelism at the level of the object or statement. If you do not explicitly specify an object in the indicator, then parallelism occurs at the level of instruction.

  Then, this article explains the difference between the EDUCATIONAL level and OBJECT level parallelism and includes a code example.

  And article 3 of the code example shows this:

  3 run the following SELECT statement:

  SELECT / * + PARALLEL (4) * / hr_emp.last_name, d.department_name
  Hr_emp, departments d employees
  WHERE the hr_emp.department_id = d.department_id;
  Because there is no schema object specified in the PARALLEL indication, the scope of the indicator is education, not an object. This statement requires the request of employees and departments to run with a degree of parallelism to 4, tables substituting defined on tables parallelism setting.

  All this took less than 5 minutes and EXACTLY answer your question!

  The documentation is your friend.

  I suggest that a break of Oracle and research of tutorials on the internet about how to search the Internet. Until you learn how to search effectively on the internet, you will continue to have problems, find answers.

• How Oracle use Index?

  RDBMS 11.2.0.3
  
  Hi all
  
  Suppose I have create the following table and the primary key:

  CREATE TABLE DUMMY_I( BOC NUMBER, START_TIME DATE, END_TIME DATE);
  
  ALTER TABLE DUMMY_I  
  MODIFY (BOC NOT NULL);
  
  ALTER TABLE DUMMY_I  
  MODIFY (START_TIME NOT NULL);
  
  ALTER TABLE DUMMY_I
  ADD CONSTRAINT DUMMY_I_PK PRIMARY KEY 
  ( BOC, START_TIME) ENABLE;

  A query with Oracle will use a PK Index:

  SELECT * FROM
  DUMMY_I 
  WHERE BOC = :v01
  AND START_TIME = :v02

  But the my dobout is when I need to add field in my query:
  

  SELECT * FROM
  DUMMY_I
  WHERE  BOC = :v01
  AND START_TIME = :v02
  AND END_TIME != :v03

  In the example above: how to create an Index to optimize my request?
  
  Given that BOC and START_TIME already have an index. Then I should create an Index unique addition field END_TIME and Oracle will use both indexes to optimize my request?
  Or
  I need to create a new Index with BOC, START_TIME, END_TIME?

  Hello

  Take a look at this, especially the Index scan to the chapter

  http://docs.Oracle.com/CD/E29597_01/server.1111/e16638/optimops.htm#autoId9

  Oracle uses indexes in several different ways, which will have much more to understand than a forum thread
  of course, if you have a specific question, pull :)

  on your original question:

  both cases are possible, but

  (a) index on BOC, START_TIME, END_TIME - its pretty simple so that it works and as simple good

  (b) index on BOC, START_TIME and END_TIME index
  Oracle can (but not necessarily will!) use both indexes in a JOIN INDEX, also a long time that you reference that these and any additional unindexed columns (if there is one)

  Given this example with queries, one is more appropriate here, but he cannot say in general.

• System tablespace allocation how oracle determines the size of the measure

  Hello
  
  It may be a silly question, but the I must request and obtain a few knowdge
  
  Assume that the allocation_type tablespace is system so how oracle determines the initial measurement and size max measure?

  Osama has provided useful links to the information you need. I'll just add with locally managed tablespace that the maximum number of spans is always unlimited even if you specify a value in the storage of declaration of establishment clause. Oracle does not take into account the value you provide and will with unlimited. I consider this unfortunate since in most cases, I know how large tables can reach and if the table extends beyond that point a developer made a mistake.

  HTH - Mark D Powell.

• How oracle decide whetehr to use the index or full analysis (statistics)

  Hi guys,.
  
  Let's say I have an index on a column.
  Tables and index statistics were collected. (without the histograms).
  
  Let's say I have run a select * from table where a = 5;
  Oracle will perform a complete analysis.
  But what statistics, it will be able to know indeed the greater part of the column = 5? (histograms do not used)
  
  After analysis, we get the following:
  Statistical table:
  (NUM_ROWS)
  (BLOCKS)
  (EMPTY_BLOCKS)
  (AVG_SPACE)
  (CHAIN_COUNT)
  (AVG_ROW_LEN)
  
  Index statistics:
  (BLEVEL)
  (LEAF_BLOCKS)
  (DISTINCT_KEYS)
  (AVG_LEAF_BLOCKS_PER_KEY)
  (AVG_DATA_BLOCKS_PER_KEY)
  (CLUSTERING_FACTOR)
  
  Thank you
  
  
  
  
  
  Index of column (A)
  ======
  1
  1
  2
  2
  5
  5
  5
  5
  5
  5

  I have prepared a few explanations and did not notice that the topic has been marked as answer.

  My sentence is not quite true.

  A column "without histograms' means that the column has only a bucket.

  More correct: even without the histogram there are data in dba_tab_histograms which can be considered a bucket for the whole column. In fact, these data are extracted from hist_head$, not from $ histgrm as usual buckets.
  Technically there are no buckets without combined histograms.

  Let's create a table with the asymmetric data distribution.

  SQL> create table t as
    2  select least(rownum,3) as val, '*' as pad
    3    from dual
    4  connect by level <= 1000000;
  
  Table created
  
  SQL> create index idx on t(val);
  
  Index created
  
  SQL> select val, count(*)
    2    from t
    3   group by val;
  
         VAL   COUNT(*)
  ---------- ----------
           1          1
           2          1
           3     999998
  

  So, we have table with the very uneven distribution of the data.
  We collect statistics without histograms.

  SQL> exec dbms_stats.gather_table_stats( user, 'T', estimate_percent => 100, method_opt => 'for all columns size 1', cascade => true);
  
  PL/SQL procedure successfully completed
  
  SQL> select blocks, num_rows  from dba_tab_statistics
    2   where table_name = 'T';
  
      BLOCKS   NUM_ROWS
  ---------- ----------
        3106    1000000
  
  SQL> select blevel, leaf_blocks, clustering_factor
    2    from dba_ind_statistics t
    3   where table_name = 'T'
    4     and index_name = 'IDX';
  
      BLEVEL LEAF_BLOCKS CLUSTERING_FACTOR
  ---------- ----------- -----------------
           2        4017              3107
  
  SQL> select column_name,
    2         num_distinct,
    3         density,
    4         num_nulls,
    5         low_value,
    6         high_value
    7    from dba_tab_col_statistics
    8   where table_name = 'T'
    9     and column_name = 'VAL';
  
  COLUMN_NAME  NUM_DISTINCT    DENSITY  NUM_NULLS      LOW_VALUE      HIGH_VALUE
  ------------ ------------ ---------- ---------- -------------- ---------------
  VAL                     3 0,33333333          0           C102            C104
  

  Therefore, Oracle suggests that the values between 1 and 3 (raw C102 C104) are distributed uniform and the density of the distribution is 0.33.
  We will try to explain the plan

  SQL> explain plan for
    2  select --+ no_cpu_costing
    3         *
    4    from t
    5   where val = 1
    6  ;
  
  Explained
  
  SQL> @plan
  
  --------------------------------------------------
  | Id  | Operation         | Name | Rows  | Cost  |
  --------------------------------------------------
  |   0 | SELECT STATEMENT  |      |   333K|   300 |
  |*  1 |  TABLE ACCESS FULL| T    |   333K|   300 |
  --------------------------------------------------
  Predicate Information (identified by operation id):
  ---------------------------------------------------
     1 - filter("VAL"=1)
  Note
  -----
     - cpu costing is off (consider enabling it)
  

  An excerpt from trace 10053

  BASE STATISTICAL INFORMATION
  ***********************
  Table Stats::
    Table:  T  Alias:  T
      #Rows: 1000000  #Blks:  3106  AvgRowLen:  5.00
  Index Stats::
    Index: IDX  Col#: 1
      LVLS: 2  #LB: 4017  #DK: 3  LB/K: 1339.00  DB/K: 1035.00  CLUF: 3107.00
  ***************************************
  SINGLE TABLE ACCESS PATH
    -----------------------------------------
    BEGIN Single Table Cardinality Estimation
    -----------------------------------------
    Column (#1): VAL(NUMBER)
      AvgLen: 3.00 NDV: 3 Nulls: 0 Density: 0.33333 Min: 1 Max: 3
    Table:  T  Alias: T
      Card: Original: 1000000  Rounded: 333333  Computed: 333333.33  Non Adjusted: 333333.33
    -----------------------------------------
    END   Single Table Cardinality Estimation
    -----------------------------------------
    Access Path: TableScan
      Cost:  300.00  Resp: 300.00  Degree: 0
        Cost_io: 300.00  Cost_cpu: 0
        Resp_io: 300.00  Resp_cpu: 0
    Access Path: index (AllEqRange)
      Index: IDX
      resc_io: 2377.00  resc_cpu: 0
      ix_sel: 0.33333  ix_sel_with_filters: 0.33333
      Cost: 2377.00  Resp: 2377.00  Degree: 1
    Best:: AccessPath: TableScan
           Cost: 300.00  Degree: 1  Resp: 300.00  Card: 333333.33  Bytes: 0
  

  FTS here costs 300 and Index Range Scan here costs 2377.
  I disabled cpu cost, so the selectivity does not affect the cost of FTS.
  cost of the Index Range Scan is calculated as
  blevel + (leaf_blocks * selectivity + clustering_factor * selecivity) = 2 + (4017 * 0.33333 + 3107 * 0.33333) = 2377.
  Oracle believes that he must read 2 blocks root/branch index, 1339 the index leaf blocks and 1036 blocks in the table.
  Pay attention that the selectivity is the main component of the cost of the Index Range Scan.

  We will try to collect histograms:

  SQL> exec dbms_stats.gather_table_stats( user, 'T', estimate_percent => 100, method_opt => 'for columns val size 3', cascade => true);
  
  PL/SQL procedure successfully completed
  

  If you look at dba_tab_histograms you can see more

  SQL> select endpoint_value,
    2         endpoint_number
    3    from dba_tab_histograms
    4   where table_name = 'T'
    5     and column_name = 'VAL'
    6  ;
  
  ENDPOINT_VALUE ENDPOINT_NUMBER
  -------------- ---------------
               1               1
               2               2
               3         1000000
  

  ENDPOINT_VALUE is the value of the column (in number for any type of data) and ENDPOINT_NUMBER is the cumulative number of lines.
  Number of lines for any ENDPOINT_VALUE = ENDPOINT_NUMBER for this ENDPOINT_VALUE - ENDPOINT_NUMBER to the previous ENDPOINT_VALUE.

  explain the plan and track 10053 the same query:

  ------------------------------------------------------------
  | Id  | Operation                   | Name | Rows  | Cost  |
  ------------------------------------------------------------
  |   0 | SELECT STATEMENT            |      |     1 |     4 |
  |   1 |  TABLE ACCESS BY INDEX ROWID| T    |     1 |     4 |
  |*  2 |   INDEX RANGE SCAN          | IDX  |     1 |     3 |
  ------------------------------------------------------------
  Predicate Information (identified by operation id):
  ---------------------------------------------------
     2 - access("VAL"=1)
  Note
  -----
     - cpu costing is off (consider enabling it)
  

  ***************************************
  BASE STATISTICAL INFORMATION
  ***********************
  Table Stats::
    Table:  T  Alias:  T
      #Rows: 1000000  #Blks:  3106  AvgRowLen:  5.00
  Index Stats::
    Index: IDX  Col#: 1
      LVLS: 2  #LB: 4017  #DK: 3  LB/K: 1339.00  DB/K: 1035.00  CLUF: 3107.00
  ***************************************
  SINGLE TABLE ACCESS PATH
    -----------------------------------------
    BEGIN Single Table Cardinality Estimation
    -----------------------------------------
    Column (#1): VAL(NUMBER)
      AvgLen: 3.00 NDV: 3 Nulls: 0 Density: 5.0000e-07 Min: 1 Max: 3
      Histogram: Freq  #Bkts: 3  UncompBkts: 1000000  EndPtVals: 3
    Table:  T  Alias: T
      Card: Original: 1000000  Rounded: 1  Computed: 1.00  Non Adjusted: 1.00
    -----------------------------------------
    END   Single Table Cardinality Estimation
    -----------------------------------------
    Access Path: TableScan
      Cost:  300.00  Resp: 300.00  Degree: 0
        Cost_io: 300.00  Cost_cpu: 0
        Resp_io: 300.00  Resp_cpu: 0
    Access Path: index (AllEqRange)
      Index: IDX
      resc_io: 4.00  resc_cpu: 0
      ix_sel: 1.0000e-06  ix_sel_with_filters: 1.0000e-06
      Cost: 4.00  Resp: 4.00  Degree: 1
    Best:: AccessPath: IndexRange  Index: IDX
           Cost: 4.00  Degree: 1  Resp: 4.00  Card: 1.00  Bytes: 0
  

  Be careful on selectivity, ix_sel: 1.0000e - 06
  Cost of the FTS is always the same = 300,
  but the cost of the Index Range Scan is now 4: 2 blocks from root/branch + block 1 sheet + 1 table blocks.

  So, conclusion: histograms to calculate more accurate selectivity. The goal is to have more efficient execution plans.

  Alexander Anokhin
  http://alexanderanokhin.WordPress.com/

• How Oracle calclutes the cost for table analysis with non-voltage costs CPU.

  If the CPU costing are disabled and the column of blocks shown 1000 for a table in the user_tables and DB a DB_BLOCK_SIXE = 8KB and DB_FILE_MULTIBLOCK_READ_COUNT = 8.
  
  What will be the cost of a complete analysis of the table? How it will be calculated.

  user445775 wrote:
  Thanks Randolf,

  Infact I'm reading the same book and I was confused with the "adjusted" way MBRC is calculated?
  is it remain static in the database if I don't change MBRC? If not what are the factors can change the MBRC "adjusted".

  I recommend to download the code repository and run the script 'calc_mbrc.sql '. For each MBRC, it will show you the corresponding MBRC "amended". This looks like an adjustment factor "coded", static, built-in that simply depends on the defined MBRC, so for example if you use MBRC = 16, 10.40 is used as MBRC "adjusted", if you use a 64 MBRC a MBRC "adjusted" 25,84 will be used for the calculation (note how the largest EEG MBRCs and a more pessimistic "adjusted" value) etc.

  Kind regards
  Randolf

  Oracle related blog stuff:
  http://Oracle-Randolf.blogspot.com/

  SQLTools ++ for Oracle (Open source Oracle GUI for Windows):
  http://www.sqltools-plusplus.org:7676 /.
  http://sourceforge.NET/projects/SQLT-pp/

• Me and my dad is from the same Apple ID and I want to set up his own, but how it will get all his contacts, photos etc from my Apple ID? Or he will lose all? or I could keep them saved for him and send more via an application any?

  Me and my dad is from the same Apple ID and I want to set up his own, but how it will get all his contacts, photos etc from my Apple ID? Or he will lose all? or I could keep them saved for him and send more via an application any? I don't know how to resolve this issue, if someone could point me in the right direction.

  Have him create a id Apple here- create and start using a Apple - Apple Support ID, and then both you can create an album-photo sharing Photo Sharing - Apple Support iCloud