I have just discovered that I can issue this below!
ALTER INDEX <*INDEX_NAME> *REBUILD REVERSE
But, unfortunately to my case, I can't perform this on a partitioned index.
*--*
*Att*
*Luis Santos*
2017-10-31 11:47 GMT-02:00 Luis Santos <lsantos@xxxxxxxxx>:
Using the online clause of the create index statement will force the table
to be read instead.
Thanks Andrew! This option worked like a charm. I got the plan with the
expected FULL SCAN.
But, weird, the plan shows the exact same time as before.
[11g]> explain plan for
2 CREATE UNIQUE INDEX "OWNER_O"."PK_TABLE_NAME1" ON
"OWNER_O"."TABLE_NAME1" L ("ID_TABLE_NAME1", "DATA") REVERSE
3 PCTFREE 10 INITRANS 2 MAXTRANS 255
4 STORAGE(
5 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
6 TABLESPACE "CRIVO_INDEX" LOCAL
7 parallel 64
8 ONLINE
9 /
Explicado.
Decorrido: 00:00:00.30
U71013576@P01CRV.brux0387 [11g]> @xplan
PLAN_TABLE_OUTPUT
------------------------------------------------------------
------------------------------------------------------------
----------------------------------
Plan hash value: 2391156251
------------------------------------------------------------
------------------------------------------------------------
---------------------
| Id | Operation | Name | Rows | Bytes |
Cost (%CPU)| Time | Pstart| Pstop | TQ |IN-OUT| PQ Distrib |
------------------------------------------------------------
------------------------------------------------------------
---------------------
| 0 | CREATE INDEX STATEMENT | | 7462M| 111G|
124K (1)| 00:24:58 | | | | | |
| 1 | PX COORDINATOR | | | |
| | | | | | |
| 2 | PX SEND QC (RANDOM) | :TQ10000 | 7462M| 111G|
| | | | Q1,00 | P->S | QC (RAND) |
| 3 | PX PARTITION RANGE ALL | | 7462M| 111G|
| | 1 | 28 | Q1,00 | PCWC | |
| 4 | INDEX BUILD UNIQUE (LOCAL)| PK_TABLE_NAME1 | | |
| | 1 | 28 | Q1,00 | PCWP | |
| 5 | SORT CREATE INDEX | | 7462M| 111G|
| | | | Q1,00 | PCWP | |
| 6 | TABLE ACCESS FULL | TABLE_NAME1 | 7462M| 111G|
124K (1)| 00:24:58 | 1 | 28 | Q1,00 | PCWP | |
------------------------------------------------------------
------------------------------------------------------------
---------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - CRI$1
6 - CRI$1 / L@CRI$1
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - SYSDEF[272], SYSDEF[4]
2 - (#keys=0) SYSDEF[272], SYSDEF[4]
3 - SYSDEF[272], SYSDEF[4]
4 - SYSDEF[272]
5 - (#keys=2) REVERSE("ID_TABLE_NAME1")[22], REVERSE("DATA")[7],
"L".ROWID[ROWID,10]
6 - "L".ROWID[ROWID,10], "ID_TABLE_NAME1"[NUMBER,22], "DATA"[DATE,7]
And the table TABLE_NAME1 has 403 Gb, and its PK_TABLE_NAME1 has 259 Gb.
*--*
*Att*
*Luis Santos*
2017-10-25 17:58 GMT-02:00 Andy Sayer <andysayer@xxxxxxxxx>:
Using the online clause of the create index statement will force the
table to be read instead.
Regards,
Andrew
On Wed, 25 Oct 2017 at 20:54, Luis Santos <lsantos@xxxxxxxxx> wrote:
Ok, it's here. First our DB version and PSU.
[11g]> @psu
COMMENTS VERSION
--------------------------------------------------
------------------------------
PSU 11.2.0.4.170814 11.2.0.4
Note that I tried to use hints on CREATE INDEX command. Look the
article: https://blog.pythian.com/oracles-create-index-comma
nd-can-take-hint
But they did not work.
[11g]> explain plan forPlan hash value: 961639110
2 CREATE /*+ NO_INDEX(L PK_TABLE_NAME1) FULL(L) */ UNIQUE INDEX
"OWNER_O"."PK_TABLE_NAME1" ON "OWNER_O"."TABLE_NAME1" L ("ID_TABLE_NAME1",
"DATA") REVERSE
3 PCTFREE 10 INITRANS 2 MAXTRANS 255
4 STORAGE(
5 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
6 TABLESPACE "CRIVO_INDEX" LOCAL
7 parallel 64
8 /
Explicado.
U71013576@P01CRV.brux0387 [11g]> @xplan
PLAN_TABLE_OUTPUT
------------------------------------------------------------
------------------------------------------------------------
------------------------------------------------------------
------------------------------------------------------------| 4 | INDEX BUILD UNIQUE (LOCAL)| PK_TABLE_NAME1 | | |
------------------------------------------------------------
---------------------
| Id | Operation | Name | Rows | Bytes
| Cost (%CPU)| Time | Pstart| Pstop | TQ |IN-OUT| PQ Distrib |
------------------------------------------------------------
------------------------------------------------------------
---------------------
| 0 | CREATE INDEX STATEMENT | | 7462M|
111G| 292K (1)| 00:58:27 | | | | |
|
| 1 | PX COORDINATOR | | |
| | | | | | | |
| 2 | PX SEND QC (RANDOM) | :TQ10000 | 7462M|
111G| | | | | Q1,00 | P->S | QC (RAND) |
| 3 | PX PARTITION RANGE ALL | | 7462M|
111G| | | 1 | 28 | Q1,00 | PCWC | |
| | 1 | 28 | Q1,00 | PCWP | || 5 | SORT CREATE INDEX | | 7462M| 111G|
| | | | Q1,00 | PCWP | || 6 | INDEX FAST FULL SCAN | PK_TABLE_NAME1 | 7462M|
111G| 124K (1)| 00:24:58 | 1 | 28 | Q1,00 | PCWP | |------------------------------------------------------------
------------------------------------------------------------6 - CRI$1 / L@CRI$1
---------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - CRI$1
Column Projection Information (identified by operation id):5 - (#keys=2) REVERSE("ID_TABLE_NAME1")[22], REVERSE("DATA")[7],
-----------------------------------------------------------
1 - SYSDEF[272], SYSDEF[4]
2 - (#keys=0) SYSDEF[272], SYSDEF[4]
3 - SYSDEF[272], SYSDEF[4]
4 - SYSDEF[272]
"L".ROWID[ROWID,10]
6 - "L".ROWID[ROWID,10], "ID_TABLE_NAME1"[NUMBER,22], "DATA"[DATE,7]
Note
-----
- estimated index size: 225G bytes
*--*
*Att*
*Luis Santos*
2017-10-25 12:32 GMT-02:00 Mark W. Farnham <mwf@xxxxxxxx>:
Would you add the actual SQL text you submitted?
mwf
*From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@freeli
sts.org] *On Behalf Of *Luis Santos
*Sent:* Wednesday, October 25, 2017 10:10 AM
*To:* ORACLE-L
*Subject:* Estimating a PK index rebuild with REVERSE
Hi Oracle-L,
I'm trying to estimate the time necessary to recreate a PK index with
the reverse clause. Usually I use explain plan to estimate time and size
for a new index.
I did a reverse script from the actual PK index using and DBMS_METADATA
and issued the explain plan, adding the reverse clause.
It worked nicely, and the output was.
[11g]> @xplan
PLAN_TABLE_OUTPUT
------------------------------------------------------------
------------------------------------------------------------
---------------------------
Plan hash value: 961639110
------------------------------------------------------------
------------------------------------------------------------
---------------------
| Id | Operation | Name | Rows | Bytes
| Cost (%CPU)| Time | Pstart| Pstop | TQ |IN-OUT| PQ Distrib |
------------------------------------------------------------
------------------------------------------------------------
---------------------
| 0 | CREATE INDEX STATEMENT | | 7462M|
111G| 292K (1)| 00:58:27 | | | | |
|
| 1 | PX COORDINATOR | | |
| | | | | | | |
| 2 | PX SEND QC (RANDOM) | :TQ10000 | 7462M|
111G| | | | | Q1,00 | P->S | QC (RAND) |
| 3 | PX PARTITION RANGE ALL | | 7462M|
111G| | | 1 | 28 | Q1,00 | PCWC | |
| 4 | INDEX BUILD UNIQUE (LOCAL)| PK_TABLE_DATA1 | |
| | | 1 | 28 | Q1,00 | PCWP | |
| 5 | SORT CREATE INDEX | | 7462M|
111G| | | | | Q1,00 | PCWP | |
| 6 | INDEX FAST FULL SCAN | PK_TABLE_DATA1 | 7462M|
111G| 124K (1)| 00:24:58 | 1 | 28 | Q1,00 | PCWP | |
------------------------------------------------------------
------------------------------------------------------------
---------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - CRI$1
6 - CRI$1 / TABLE_DATA1@CRI$1
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - SYSDEF[272], SYSDEF[4]
2 - (#keys=0) SYSDEF[272], SYSDEF[4]
3 - SYSDEF[272], SYSDEF[4]
4 - SYSDEF[272]
5 - (#keys=2) REVERSE("ID_TABLE_DATA1")[22], REVERSE("DATA")[7],
"TABLE_DATA1".ROWID[ROWID,10]
6 - "TABLE_DATA1".ROWID[ROWID,10], "ID_TABLE_DATA1"[NUMBER,22],
"DATA"[DATE,7]
Note
-----
- estimated index size: 225G bytes
But this is the evaluation phase. The PK was not, of course, already
dropped. So the actual non reverse PK index is been used in the create
index plan...
How can I disable the access to the actual PK for this explain plan?
Best regards,
*Luis Santos*
