db2 执行计划的解读 - myfriend2010的个人空间 - ITPUB个人空间 - powered by X-Space

db2exfmt o Table Operators                                             ITPUB个人空间TU3U&k5y0C@5_+A5O
db2exfmt     TBSCAN - Table Scan                                       ITPUB个人空间
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db2exfmt     IXSCAN - Index Scan
BaFM,hD#oB_0db2exfmt     FETCH  - Fetch from Table
d8etM2H*r~x.G9edq0db2exfmt                                                               ITPUB个人空间JT3]N/wz
db2exfmt o Joins
aeE-Y3w:R0db2exfmt     MSJOIN - Merge Scan Join                                  ITPUB个人空间ep3fsa;F
db2exfmt     NLJOIN - Nested Loop Join                                 ITPUB个人空间.c$P/t2o/U})i
db2exfmt     HSJOIN - Hash Join
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6k.DMbd/P0db2exfmt o Aggregation                                                 ITPUB个人空间:|F+j-P'll8s,@7~Q
db2exfmt     GRPBY  - Group By                                         ITPUB个人空间)H;G-G1L(W
db2exfmt     SUM    - Sum                                              ITPUB个人空间5MO)c*y:~.}!rX
db2exfmt     AVG    - Average                                          ITPUB个人空间.k%a}T,v'r|"ZP
db2exfmt     MIN    - Minimum                                          ITPUB个人空间Uut#a1I
db2exfmt     MAX    - Maximun                                          ITPUB个人空间Qw5\+oMM }
db2exfmt     etc.
~C'moOnJ0db2exfmt                                                               ITPUB个人空间 `)F5O(lOEDB
db2exfmt o Temp / Sort                                                 ITPUB个人空间8R\s{j'P8QD
db2exfmt     TEMP   - Insert into temp table                           ITPUB个人空间a?v
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db2exfmt     SORT   - Sort
:uxo&Dn/sg/k }0db2exfmt                                                               ITPUB个人空间;TC2q8`)i'H5I|8]
db2exfmt o Special Operations
Q0[0V6n)e0db2exfmt     IXAND  - Index ANDing
3YE.R.VlB0db2exfmt     RIDSCA - Index ORing or List Prefetch                     ITPUB个人空间*uGfjF5VO1X
db2exfmt     IXA    - Star Schema Bitmap Indexing                      ITPUB个人空间!vbB;{pz@;r)}
db2exfmt     BTQ    - Broadcast Table Queue
CG.T.@0NK9p0db2exfmt     DTQ    - Directed Table Queue                             ITPUB个人空间CQ }-f/`5FG_.d0xC!f
db2exfmt     MBTQ   - Merge Broadcast Table Queue                      ITPUB个人空间.I[/i&_
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db2exfmt     MDTQ   - Merge Directed Table Queue
#Int*c&G0db2exfmt     LTQ    - Local Table Queue, for Intra-partition parallelism
+-------------------------------+-----------------------+-----------------------+ITPUB个人空间F[
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| Join Strategy                 | Inner Table           | Outer Table           |ITPUB个人空间
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+-------------------------------+-----------------------+-----------------------+ITPUB个人空间3^V0T5h;Y&O(A#{f
| Collocated Join               | Temporary Table       | Temporary Table       |
\9|"v*M_2vH'r0+-------------------------------+-----------------------+-----------------------+ITPUB个人空间 J,UpV;I:L0SJ9f
| Directed Inner Join           | Temporary Table       | Hashed Table Queue    |
F2K"DF%O$X0| Directed Outer Join           | Hashed Table Queue    | Temporary Table       |
V'Rn \-}P_J,O;]&o0| Directed Inner and Outer Join | Hashed Table Queue    | Hashed Table Queue    |ITPUB个人空间c'X'o2}1Yj
+-------------------------------+-----------------------+-----------------------+
TK"_zI?l$pC1]0| Broadcast Inner Join          | Temporary Table       | Broadcast Table Queue |ITPUB个人空间[nbs#P'x9n
| Boradcast Outer Join          | Broadcast Table Queue | Temporary Table       |ITPUB个人空间x2vY2h~s,Z%_/iG
+-------------------------------+-----------------------+-----------------------+
附:
 
BTQ   Broadcast Table Queue broadcasts data to several partitions.
DELETE   Deletes rows from a table.
DTQ   Directed Table Queue transfers data to a specific partition.
EISCAN   Scans a user-defined index to produce a reduced stream of rows.
FETCH   Fetches columns from a table using spe-cific record identifier.
FILTER   Represents the application of residual predicates.
GRPBY   Groups rows by common values of desig-nated columns or functions.
HSJOIN   Represents a hash join, where two or more tables are hashed on join columns.
INSERT   Inserts rows into a table.
IXAND   ANDs together the row identifiers (RIDs) from two or more index scans.
IXSCAN   Scans an index of a table with optional start/stop conditions, producing an ordered stream of rows.
LTQ   Local Table Queue. Transfers data between local agents.
LMTQ   Local Merge Table Queue. Merges data transferred between local agents.
MBTQ   Merging Broadcast Table Queue.
MDTQ   Merging Directed Table queue.
MSJOIN   Represents a merge join, where both outer and inner tables must be in join-predicate order.
NLJOIN   Represents a nested loop join that accesses an inner table once for each row of the outer table.
RETURN   Represents the return of data from the query to the user.
RIDSCAN   Scans a list of row identifiers (RIDs) obtained from one or more indexes.
RPD   For nonrelational wrappers, it shows the simulatedSQL operation that the nonrela-tional wrapper will be asked to perform.
SHIP   Retrieves data from a remote database source. Used in federated systems.
SORT   Sorts rows in the order of specified col-umns, and optionally eliminates duplicate entries.
TBSCAN   Retrieves rows by reading all required data directly from the data pages.
TEMP   Stores data in a temporary table to be read back out (possibly multiple times).
TQUEUE   Transfers table data between agents.
UNION   Concatenates streams of rows from multi-ple tables.
UNIQUE   Eliminates rows with duplicate values, for specified columns.
UPDATE   Updates rows in a table.