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Regarding Multi-Threading
Post 78496 by mbb on Wednesday 20th of July 2005 05:54:40 AM
07-20-2005
Sorry to hear that you cannot stop the querying process. This will limit your options.
Insert cursors are a way for your Esql/C process to buffer the inserts before they are committed to the database. I cannont comment on how that will affect the performance of your system overall, you would have to measure that. But they are the fastest way for you to insert records into a table via your program. After your load has been completed I recommend you still run update statistics.
As far a performance goes, you may want to pre-process the file and peform your validations before you attempt an insert run. Any exception records can be excluded from the insert run.
Since you have to run a large load in the exisiting environment and it is a one off, my best suggestion would be to validate and then load the file in much smaller chunks. Say 10,000 records at a time.
Therefore split the file into multiple files of 10,000 record chunks.
Write a validation program to validate a single file.
Write a load program to load a single file.
If you dont want to manage this all manually then,
write another(!) program to manage the loading of the small 10K files. You could create a table to store the name of the file, total number of rows, number of rows validated, rows loaded. This program would limit the number of concurrent loading processes (e.g. 10 at a time) and continue until all files have completed. You could add extra features such a reloading a failed file or allowing processing during a specific time frame.
Overall the loading process may take some time to complete, but I think you are now in a situation where you should be trying to spread and manage the workload.
Anyway, given all that you have told me that is how I would approach this task and I do appreciate that what I have described is not a trivial piece of work. (Loading high volumes of data to a live database never is
)
MBB
Insert cursors are a way for your Esql/C process to buffer the inserts before they are committed to the database. I cannont comment on how that will affect the performance of your system overall, you would have to measure that. But they are the fastest way for you to insert records into a table via your program. After your load has been completed I recommend you still run update statistics.
As far a performance goes, you may want to pre-process the file and peform your validations before you attempt an insert run. Any exception records can be excluded from the insert run.
Since you have to run a large load in the exisiting environment and it is a one off, my best suggestion would be to validate and then load the file in much smaller chunks. Say 10,000 records at a time.
Therefore split the file into multiple files of 10,000 record chunks.
Write a validation program to validate a single file.
Write a load program to load a single file.
If you dont want to manage this all manually then,
write another(!) program to manage the loading of the small 10K files. You could create a table to store the name of the file, total number of rows, number of rows validated, rows loaded. This program would limit the number of concurrent loading processes (e.g. 10 at a time) and continue until all files have completed. You could add extra features such a reloading a failed file or allowing processing during a specific time frame.
Overall the loading process may take some time to complete, but I think you are now in a situation where you should be trying to spread and manage the workload.
Anyway, given all that you have told me that is how I would approach this task and I do appreciate that what I have described is not a trivial piece of work. (Loading high volumes of data to a live database never is
)MBB
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LEARN ABOUT OSX
modules-load.d
MODULES-LOAD.D(5) modules-load.d MODULES-LOAD.D(5) NAME
modules-load.d - Configure kernel modules to load at boot SYNOPSIS
/etc/modules-load.d/*.conf /run/modules-load.d/*.conf /usr/lib/modules-load.d/*.conf DESCRIPTION
systemd-modules-load.service(8) reads files from the above directories which contain kernel modules to load during boot in a static list. Each configuration file is named in the style of /etc/modules-load.d/program.conf. Note that it is usually a better idea to rely on the automatic module loading by PCI IDs, USB IDs, DMI IDs or similar triggers encoded in the kernel modules themselves instead of static configuration like this. In fact, most modern kernel modules are prepared for automatic loading already. CONFIGURATION FORMAT
The configuration files should simply contain a list of kernel module names to load, separated by newlines. Empty lines and lines whose first non-whitespace character is # or ; are ignored. CONFIGURATION DIRECTORIES AND PRECEDENCE
Configuration files are read from directories in /etc/, /run/, and /lib/, in order of precedence. Each configuration file in these configuration directories shall be named in the style of filename.conf. Files in /etc/ override files with the same name in /run/ and /lib/. Files in /run/ override files with the same name in /lib/. Packages should install their configuration files in /lib/. Files in /etc/ are reserved for the local administrator, who may use this logic to override the configuration files installed by vendor packages. All configuration files are sorted by their filename in lexicographic order, regardless of which of the directories they reside in. If multiple files specify the same option, the entry in the file with the lexicographically latest name will take precedence. It is recommended to prefix all filenames with a two-digit number and a dash, to simplify the ordering of the files. If the administrator wants to disable a configuration file supplied by the vendor, the recommended way is to place a symlink to /dev/null in the configuration directory in /etc/, with the same filename as the vendor configuration file. If the vendor configuration file is included in the initrd image, the image has to be regenerated. EXAMPLE
Example 1. /etc/modules-load.d/virtio-net.conf example: # Load virtio-net.ko at boot virtio-net SEE ALSO
systemd(1), systemd-modules-load.service(8), systemd-delta(1), modprobe(8) systemd 237 MODULES-LOAD.D(5)