Index Usage – 1
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In 12.2 Oracle introduced Index Usage Tracking to replace the previous
option for “alter index xxx monitoring usage”. A recent post on the Oracle
database ...
Acum 3 zile
You've got to have a dream. When you lose your dreams, you die.
https://www.oratoolkit.ch/knowledge/howto/installation/seSrv-11g-R2-on-OEL-6.3-x86_64.php
Exadata Rack | Disk Type | Disk Count | Disk Model | IOPS |
FULL (1/1) | HP | 14 * 12 = 168 | 15000rpm SAS 600G | 50000 |
HC | 7200rpm SAS 3T | 28000 | ||
HALF (1/2) | HP | 7 * 12 = 68 | 15000rpm SAS 600G | 25000 |
HC | 7200rpm SAS 3T | 14000 | ||
QUAR (1/4) | HP | 3 * 12 = 36 | 15000rpm SAS 600G | 10800 |
HC | 7200rpm SAS 3T | 6000 |
mkfs -t ext3 -b 4096 /dev/sda2
320GB | 640GB | |
NAND Type | MLC (Multi Level Cell) | MLC (Multi Level Cell) |
Read Bandwidth (64kB) | 735 MB/s | 750 MB/s |
Write Bandwidth (64kB) | 510 MB/s | 550 MB/s |
Read IOPS (512 Byte) | 100,000 | 93,000 |
Write IOPS (512 Byte) | 141,000 | 145,000 |
Mixed IOPS (75/25 r/w) | 67,000 | 74,000 |
Access Latency (512 Byte) | 30 µs | 30 µs |
Bus Interface | PCI-Express x4 |
365GB | 785GB | 1.2 TB | |
NAND Type | MLC (Multi Level Cell) | MLC (Multi Level Cell) | MLC (Multi Level Cell) |
Read Bandwidth (1MB) | 900 MB/s | 1.5 GB/s | 1.5 GB/s |
Write Bandwidth (1MB) | 575 MB/s | 1.1 GB/s | 1.3 GB/s |
Read IOPS (Seq. 512 Byte) | 415,000 | 443,000 | 443,000 |
Write IOPS (Seq. 512 Byte) | 530,000 | 530,000 | 530,000 |
Read IOPS (Rand. 512 Byte) | 136,000 | 141,000 | 143,000 |
Write IOPS (Rand. 512 Byte) | 475,000 | 475,000 | 475,000 |
Read Access Latency | 68µs | 68µs | 68µs |
Write Access Latency | 15µs | 15µs | 15µs |
Bus Interface | PCI-Express Gen2 x4 |
x
int
default
s.nextval
primary
key
where s is a sequence
In sqlserver you would have
The following SQL statement defines the "P_Id" column to be an auto-increment primary key field in the "Persons" table:
CREATE TABLE Persons
(
P_Id int PRIMARY KEY IDENTITY,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Address varchar(255),
City varchar(255)
)
Files#getOwner()
for this.Path path = Paths.get("/path/to/file.ext");
UserPrincipal owner = Files.getOwner(path);
String username = owner.getName();