03-ORACLE数据导入导出教程.pptVIP

* * * Direct-Path Export Concepts By using the Direct-Path feature, you can extract data much faster. When the DIRECT=Y parameter is specified, the Export utility reads directly from the data layer instead of going through the SQL-command processing layer. Mechanics of Direct-Path Export ? Direct mode of export can be set by specifying the DIRECT=Y parameter. ? Direct-path export does not compete with other resources of the Instance. ? If in direct-read mode, it reads database blocks into a private area used by the session. ? Rows are transferred directly into the Two-Task Common (TTC) buffer for transport. ? The data in the TTC buffer is in the format that the Export utility expects. Oracle9i DBA Fundamentals II 18-9 * * * * * Server, not client Write your own export and import! DP stream format mirrors what’s on disk… minimal conversions required. Caveat the “superset” comment * Describe req. gathering: Perf. Was customer reqs 1, 2 3. 3. 1.5-2X exp direct path! Even faster against exp conventional 4. See me after for some tricks on how to increase original imp performance * * Explain security issue. If dmpdir1 pts to data1 and dmpdir2 to data2, then files will be created as: /data1/full101.dmp, /data2/full201.dmp, /data1/full102.dmp, /data2/full202.dmp 3. However, specified size must be large enough to hold entire Master Table at end of export. 4. File specs. Must span entire dump set at import time. * 2. XML schemas and views are not yet supported in 数据泵 5. Start a job up when leaving the office and monitor it from home. * A whole slide to the very cool interactive mode… * Explain XML 2. Original exp can’t do just data. Caveat on “truncate”: Target of ref. constraints. Append is default for data-only. * 1. Important on those few platforms that don’t support asynch I/O by default. * * The recycle bin is actually a data dictionary table containing information about dropped objects. Dropped tables and any associated objects such as indexes, constraints, nest