# Editing historian tag data

**URL:** <https://forum.inductiveautomation.com/t/editing-historian-tag-data/49328>\
**Category:** Ignition\
**Created:** [July 28, 2021, 8:46pm UTC](https://forum.inductiveautomation.com/t/editing-historian-tag-data/49328 "2021-07-28T20:46:08Z")\
**Posts on this page:** 1\
**Showing post:** 32

<div class="post-metadata">

**Author:** ![lrose](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/lrose/32/62724_2.png) [@lrose](https://forum.inductiveautomation.com/u/lrose)\
**Post date:** [August 3, 2021, 1:03pm UTC](https://forum.inductiveautomation.com/t/editing-historian-tag-data/49328/32 "2021-08-03T13:03:40Z")

</div>

> [@zacharyw.larson](#):
>
> I wonder what the time overhead is per system.tag.readblocking() I use

Throw this into your script console and run it.

```auto
from java.lang import System

tagPaths = []
ret = 0
currentTime = system.date.now()

for i in range(400):
	tagPaths.append('[Client]CurrentTime')
	

start = System.nanoTime()

for i in range(400):
	ret = system.tag.readBlocking(tagPaths[i])
	
end = System.nanoTime()

print '400 singular reads took %.3f ms' % ((end-start) / 1000000.0)

values = []
paths = []

start = System.nanoTime()

for i in range(400):
	values.append(currentTime)
	paths.append('[Client]CurrentTime')
	if i % 5 == 0:
		ret = system.tag.readBlocking(paths)
		values = []
		paths = []

end = System.nanoTime()

print '400 readss in blocks of 5 took %.3f ms' % ((end-start) / 1000000.0)

values=[]
paths = []

start = System.nanoTime()

for i in range(400):
	values.append(currentTime)
	paths.append('[Client]CurrentTime')
ret = system.tag.readBlocking(paths)

end = System.nanoTime()

print '400 reads in 1 block took %.3f ms' % ((end-start) / 1000000.0)

```

Here were the results on my system:

```auto
>>> 
400 singular reads took 16.169 ms
400 reads in blocks of 5 took 3.345 ms
400 reads in 1 block took 0.569 ms
>>> 

```

As the size of the system and load on the gateway changes these results will very, however, reading all tags at once will remain the fastest by a lot.

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