{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Comparing performance of btables in memory and cached disk" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "In this tutorial we are going to see the performance of the btable container using different compressors and compression levels, the only difference with \"Comparing speedups when using compression with blz btables stored in disk\" is that this one will work with memory and cached disk." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Reading data from disk is a really slow operation to improve loading times the operating system stores a copy of the read data into memory, so every other read is faster than the previous one. This is what is called caching and this is what I want to compare with working only with in memory BLZ. This is the normal scenario when working with data and this is why both are being compared." ] }, { "cell_type": "code", "collapsed": false, "input": [ "import pandas as pd\n", "import numpy as np\n", "import pylab as plt\n", "import blz\n", "import sys\n", "import csv\n", "from time import time\n", "from shutil import rmtree\n", "from collections import defaultdict" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 1 }, { "cell_type": "markdown", "metadata": {}, "source": [ "Let's create a btable in disk and a btable on memory." ] }, { "cell_type": "code", "collapsed": false, "input": [ "t1 = time()\n", "df = pd.read_hdf('h5/msft-18-SEP-2013-blosc9.h5', '/msft')\n", "t2 = time()\n", "\n", "print \"Reading h5: \" + str(t2 - t1)\n", "\n", "dt = np.dtype([(k, v if v.kind!='O' else 'S49') for k,v in df.dtypes.iteritems()])\n", "\n", "t1 = time()\n", "btm = blz.fromiter((i[1:] for i in df.itertuples()), dtype=dt, count=len(df), \n", " bparams=blz.bparams(clevel=0))\n", "t2 = time()\n", "\n", "print \"Converting h5 to btable in memory: \" + str(t2 - t1)\n", "\n", "#If the blz already exist, remove it\n", "rmtree('blz/msft-18-SEP-2013-blosc9.blz', ignore_errors=True)\n", "\n", "t1 = time()\n", "btd = btm.copy(rootdir='blz/msft-18-SEP-2013-blosc9.blz', bparams=blz.bparams(clevel=0))\n", "t2 = time()\n", "\n", "print \"Copying btable from memory to disk: \" + str(t2-t1)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Reading h5: 4.99775981903\n", "Converting h5 to btable in memory: 7.79994988441" ] }, { "output_type": "stream", "stream": "stdout", "text": [ "\n", "Copying btable from memory to disk: 10.7896511555" ] }, { "output_type": "stream", "stream": "stdout", "text": [ "\n" ] } ], "prompt_number": 2 }, { "cell_type": "markdown", "metadata": {}, "source": [ "We will take the [Open-High-Low-Close](http://en.wikipedia.org/wiki/Open-high-low-close_chart) points for that chart, for every level, for every compressor. This will be our \"heavy\" operation." ] }, { "cell_type": "code", "collapsed": false, "input": [ "def get_OHLC_points(src):\n", " \n", " windows = []\n", " window_size = 79\n", " sample_size = 2455\n", " \n", " iter = src.where('(Type == \\'Trade\\')')\n", "\n", " for i in xrange(sample_size):\n", " \n", " local_max = - np.inf\n", " local_min = np.inf\n", " average_price = 0\n", " \n", " for j in xrange(window_size):\n", " \n", " current = iter.next()\n", " price = current[7]\n", " average_price += price\n", " \n", " if(price > local_max):\n", " local_max = price\n", " \n", " if(price < local_min):\n", " local_min = price\n", " \n", " if(j == 0):\n", " local_open = price\n", " \n", " if(j == (window_size - 1)):\n", " local_close = price\n", " \n", " windows.append([average_price/float(window_size), local_open, local_max, local_min, local_close]) " ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 3 }, { "cell_type": "markdown", "metadata": {}, "source": [ "Let's do the copy function." ] }, { "cell_type": "code", "collapsed": false, "input": [ "def copy(src, memory, clevel=5, shuffle=True, cname=\"blosclz\"):\n", "\n", " \"\"\"\n", "\n", " Parameters\n", " ----------\n", " clevel : int (0 <= clevel < 10)\n", " The compression level.\n", " shuffle : bool\n", " Whether the shuffle filter is active or not.\n", " cname : string ('blosclz', 'lz4', 'lz4hc', 'snappy', 'zlib', others?)\n", " Select the compressor to use inside Blosc.\n", "\n", " \"\"\"\n", " if memory == True:\n", " copied = src.copy(bparams=blz.bparams(clevel=clevel, shuffle=shuffle, cname=cname))\n", " else:\n", " copied = src.copy(rootdir='blz/temp.blz', bparams=blz.bparams(clevel=clevel, shuffle=shuffle, cname=cname))\n", " \n", " copied.flush()\n", " \n", " return copied" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 4 }, { "cell_type": "markdown", "metadata": {}, "source": [ "And now we just need a benchmark function." ] }, { "cell_type": "code", "collapsed": false, "input": [ "def benchmark(data, cmethods, memory):\n", " \n", " if memory == True:\n", " base_name = 'csv/bbtablem_'\n", " else:\n", " base_name = 'csv/bbtable_'\n", "\n", " for method in cmethods:\n", "\n", " myfile = open(base_name + method + '.csv', 'wb')\n", " wr = csv.writer(myfile, quoting=csv.QUOTE_ALL)\n", " wr.writerow(['Compression level',\n", " 'Compressed size',\n", " 'Compression ratio',\n", " 'Compression time',\n", " 'OHLC time',\n", " 'Writing speed (MiB/s)',\n", " 'OHLC speed (MiB/s)'])\n", "\n", " for compression_level in xrange(0,10):\n", "\n", " #I use data so I only keep one copy in memory\n", " tc1 = time()\n", " data = copy(data, memory, compression_level, True, method)\n", " tc2 = time()\n", "\n", " #Now I get the poins and measure the time\n", " t1 = time()\n", " get_OHLC_points(data)\n", " t2 = time()\n", " \n", " #Uncompressed size in MiB\n", " uncompressed = data.nbytes/(2**20)\n", "\n", " #I should store stuff\n", " row = [compression_level, data.cbytes,\n", " round(data.nbytes/float(data.cbytes),3),\n", " str(tc2 - tc1),\n", " str(t2 - t1),\n", " uncompressed/(tc2 - tc1),\n", " uncompressed/(t2 - t1)]\n", "\n", " #Add it to the csv\n", " wr.writerow(row)\n", " rmtree('blz/temp.blz', ignore_errors=True)\n", "\n", " myfile.close()" ], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 7 }, { "cell_type": "markdown", "metadata": {}, "source": [ "We have all the ingredients now, let's do some benchmarking." ] }, { "cell_type": "code", "collapsed": false, "input": [ "cmethods = ['blosclz', 'lz4', 'lz4hc', 'snappy', 'zlib']\n", "\n", "t1 = time()\n", "benchmark(btd, cmethods, False)\n", "t2 = time()\n", "\n", "t3 = time()\n", "benchmark(btm, cmethods, True)\n", "t4 = time()\n", "\n", "print 'Cached disk: ' + str(t2-t1)\n", "print 'Memory only: ' + str(t4-t3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Cached disk: 748.564900875\n", "Memory only: 564.818388939\n" ] } ], "prompt_number": 8 }, { "cell_type": "markdown", "metadata": {}, "source": [ "We can see all the gathered data now." ] }, { "cell_type": "code", "collapsed": false, "input": [ "print 'blosclz data'\n", "print 'Memory'\n", "df = pd.read_csv('csv/bbtablem_blosclz.csv')\n", "df" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "blosclz data\n", "Memory\n" ] }, { "html": [ "
\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "0.681122 | \n", "2.263231 | \n", "675.356186 | \n", "203.249245 | \n", "
1 | \n", "1 | \n", "62562582 | \n", "7.716 | \n", "0.804646 | \n", "2.227441 | \n", "571.679958 | \n", "206.515003 | \n", "
2 | \n", "2 | \n", "60615376 | \n", "7.964 | \n", "0.828417 | \n", "2.152618 | \n", "555.276023 | \n", "213.693286 | \n", "
3 | \n", "3 | \n", "60114378 | \n", "8.030 | \n", "0.841646 | \n", "2.186049 | \n", "546.548102 | \n", "210.425294 | \n", "
4 | \n", "4 | \n", "28904306 | \n", "16.701 | \n", "0.960289 | \n", "2.399268 | \n", "479.022460 | \n", "191.725150 | \n", "
5 | \n", "5 | \n", "27821399 | \n", "17.351 | \n", "1.134386 | \n", "2.458255 | \n", "405.505687 | \n", "187.124603 | \n", "
6 | \n", "6 | \n", "27450920 | \n", "17.585 | \n", "1.142648 | \n", "2.458005 | \n", "402.573677 | \n", "187.143643 | \n", "
7 | \n", "7 | \n", "27136857 | \n", "17.789 | \n", "1.140152 | \n", "2.495144 | \n", "403.454902 | \n", "184.358105 | \n", "
8 | \n", "8 | \n", "27091198 | \n", "17.819 | \n", "1.157194 | \n", "2.430481 | \n", "397.513330 | \n", "189.262952 | \n", "
9 | \n", "9 | \n", "27033395 | \n", "17.857 | \n", "1.172375 | \n", "2.481087 | \n", "392.365936 | \n", "185.402592 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "10.990172 | \n", "3.124110 | \n", "41.855578 | \n", "147.241935 | \n", "
1 | \n", "1 | \n", "62562582 | \n", "7.716 | \n", "1.679541 | \n", "2.767619 | \n", "273.884374 | \n", "166.207841 | \n", "
2 | \n", "2 | \n", "60615376 | \n", "7.964 | \n", "1.737121 | \n", "2.741565 | \n", "264.805984 | \n", "167.787378 | \n", "
3 | \n", "3 | \n", "60114378 | \n", "8.030 | \n", "1.763058 | \n", "2.736637 | \n", "260.910313 | \n", "168.089513 | \n", "
4 | \n", "4 | \n", "28904306 | \n", "16.701 | \n", "1.857233 | \n", "2.958073 | \n", "247.680279 | \n", "155.506635 | \n", "
5 | \n", "5 | \n", "27821399 | \n", "17.351 | \n", "1.860526 | \n", "2.963732 | \n", "247.241898 | \n", "155.209715 | \n", "
6 | \n", "6 | \n", "27450920 | \n", "17.585 | \n", "1.860842 | \n", "2.876680 | \n", "247.199925 | \n", "159.906551 | \n", "
7 | \n", "7 | \n", "27136857 | \n", "17.789 | \n", "1.854447 | \n", "2.967175 | \n", "248.052367 | \n", "155.029615 | \n", "
8 | \n", "8 | \n", "27091198 | \n", "17.819 | \n", "1.871443 | \n", "3.153615 | \n", "245.799627 | \n", "145.864349 | \n", "
9 | \n", "9 | \n", "27033395 | \n", "17.857 | \n", "1.910575 | \n", "2.970001 | \n", "240.765226 | \n", "154.882104 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "0.709622 | \n", "2.190826 | \n", "648.232525 | \n", "209.966452 | \n", "
1 | \n", "1 | \n", "31210120 | \n", "15.467 | \n", "0.699199 | \n", "2.303638 | \n", "657.895714 | \n", "199.684153 | \n", "
2 | \n", "2 | \n", "31210120 | \n", "15.467 | \n", "0.757916 | \n", "2.341326 | \n", "606.927438 | \n", "196.469864 | \n", "
3 | \n", "3 | \n", "31210120 | \n", "15.467 | \n", "0.761211 | \n", "2.227152 | \n", "604.300129 | \n", "206.541820 | \n", "
4 | \n", "4 | \n", "31210120 | \n", "15.467 | \n", "0.766530 | \n", "2.341871 | \n", "600.106947 | \n", "196.424139 | \n", "
5 | \n", "5 | \n", "31210120 | \n", "15.467 | \n", "0.759634 | \n", "2.428854 | \n", "605.554766 | \n", "189.389730 | \n", "
6 | \n", "6 | \n", "31210120 | \n", "15.467 | \n", "0.770773 | \n", "2.244157 | \n", "596.803520 | \n", "204.976739 | \n", "
7 | \n", "7 | \n", "31210120 | \n", "15.467 | \n", "0.766620 | \n", "2.323864 | \n", "600.036399 | \n", "197.946181 | \n", "
8 | \n", "8 | \n", "31210120 | \n", "15.467 | \n", "0.764220 | \n", "2.250569 | \n", "601.920913 | \n", "204.392768 | \n", "
9 | \n", "9 | \n", "31210120 | \n", "15.467 | \n", "0.762074 | \n", "2.331698 | \n", "603.615927 | \n", "197.281108 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "9.310785 | \n", "2.775670 | \n", "49.405071 | \n", "165.725750 | \n", "
1 | \n", "1 | \n", "31210120 | \n", "15.467 | \n", "1.642699 | \n", "2.819540 | \n", "280.026955 | \n", "163.147179 | \n", "
2 | \n", "2 | \n", "31210120 | \n", "15.467 | \n", "1.629550 | \n", "2.790243 | \n", "282.286524 | \n", "164.860184 | \n", "
3 | \n", "3 | \n", "31210120 | \n", "15.467 | \n", "1.624146 | \n", "2.801503 | \n", "283.225772 | \n", "164.197579 | \n", "
4 | \n", "4 | \n", "31210120 | \n", "15.467 | \n", "1.620733 | \n", "2.847433 | \n", "283.822193 | \n", "161.549011 | \n", "
5 | \n", "5 | \n", "31210120 | \n", "15.467 | \n", "1.620822 | \n", "2.820628 | \n", "283.806578 | \n", "163.084253 | \n", "
6 | \n", "6 | \n", "31210120 | \n", "15.467 | \n", "1.630892 | \n", "2.913791 | \n", "282.054231 | \n", "157.869940 | \n", "
7 | \n", "7 | \n", "31210120 | \n", "15.467 | \n", "1.651789 | \n", "2.862687 | \n", "278.485941 | \n", "160.688186 | \n", "
8 | \n", "8 | \n", "31210120 | \n", "15.467 | \n", "1.661538 | \n", "2.805433 | \n", "276.851948 | \n", "163.967557 | \n", "
9 | \n", "9 | \n", "31210120 | \n", "15.467 | \n", "1.624195 | \n", "2.863090 | \n", "283.217207 | \n", "160.665572 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "0.601254 | \n", "2.203485 | \n", "765.067693 | \n", "208.760213 | \n", "
1 | \n", "1 | \n", "27466793 | \n", "17.575 | \n", "3.476439 | \n", "2.412721 | \n", "132.319307 | \n", "190.656116 | \n", "
2 | \n", "2 | \n", "23961748 | \n", "20.146 | \n", "4.512663 | \n", "2.281846 | \n", "101.935373 | \n", "201.591164 | \n", "
3 | \n", "3 | \n", "21717259 | \n", "22.228 | \n", "6.930293 | \n", "2.223672 | \n", "66.375262 | \n", "206.865027 | \n", "
4 | \n", "4 | \n", "20475242 | \n", "23.576 | \n", "13.367165 | \n", "2.200643 | \n", "34.412683 | \n", "209.029809 | \n", "
5 | \n", "5 | \n", "19908867 | \n", "24.247 | \n", "28.572774 | \n", "2.280474 | \n", "16.099242 | \n", "201.712435 | \n", "
6 | \n", "6 | \n", "19752345 | \n", "24.439 | \n", "49.155402 | \n", "2.253255 | \n", "9.358076 | \n", "204.149119 | \n", "
7 | \n", "7 | \n", "19711733 | \n", "24.489 | \n", "56.906914 | \n", "2.264541 | \n", "8.083376 | \n", "203.131680 | \n", "
8 | \n", "8 | \n", "19710950 | \n", "24.490 | \n", "57.256365 | \n", "2.243897 | \n", "8.034041 | \n", "205.000479 | \n", "
9 | \n", "9 | \n", "19710833 | \n", "24.491 | \n", "57.443949 | \n", "2.261611 | \n", "8.007806 | \n", "203.394817 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "10.022066 | \n", "3.445173 | \n", "45.898720 | \n", "133.520154 | \n", "
1 | \n", "1 | \n", "27466793 | \n", "17.575 | \n", "4.448363 | \n", "2.818698 | \n", "103.408825 | \n", "163.195919 | \n", "
2 | \n", "2 | \n", "23961748 | \n", "20.146 | \n", "5.389405 | \n", "2.779829 | \n", "85.352650 | \n", "165.477803 | \n", "
3 | \n", "3 | \n", "21717259 | \n", "22.228 | \n", "8.024240 | \n", "2.839225 | \n", "57.326301 | \n", "162.016040 | \n", "
4 | \n", "4 | \n", "20475242 | \n", "23.576 | \n", "14.552245 | \n", "2.809012 | \n", "31.610243 | \n", "163.758649 | \n", "
5 | \n", "5 | \n", "19908867 | \n", "24.247 | \n", "29.689302 | \n", "2.799546 | \n", "15.493796 | \n", "164.312356 | \n", "
6 | \n", "6 | \n", "19752345 | \n", "24.439 | \n", "50.277322 | \n", "2.786857 | \n", "9.149254 | \n", "165.060503 | \n", "
7 | \n", "7 | \n", "19711733 | \n", "24.489 | \n", "57.907075 | \n", "2.704130 | \n", "7.943762 | \n", "170.110154 | \n", "
8 | \n", "8 | \n", "19710950 | \n", "24.490 | \n", "58.364596 | \n", "2.765320 | \n", "7.881490 | \n", "166.346039 | \n", "
9 | \n", "9 | \n", "19710833 | \n", "24.491 | \n", "58.455211 | \n", "2.771683 | \n", "7.869273 | \n", "165.964147 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "0.604864 | \n", "2.201925 | \n", "760.501383 | \n", "208.908111 | \n", "
1 | \n", "1 | \n", "410696358 | \n", "1.175 | \n", "0.851744 | \n", "2.334054 | \n", "540.068418 | \n", "197.081988 | \n", "
2 | \n", "2 | \n", "410696358 | \n", "1.175 | \n", "0.853806 | \n", "2.296802 | \n", "538.764063 | \n", "200.278470 | \n", "
3 | \n", "3 | \n", "410696358 | \n", "1.175 | \n", "0.862138 | \n", "2.373132 | \n", "533.557252 | \n", "193.836669 | \n", "
4 | \n", "4 | \n", "410696358 | \n", "1.175 | \n", "0.869969 | \n", "2.308243 | \n", "528.754394 | \n", "199.285774 | \n", "
5 | \n", "5 | \n", "410696358 | \n", "1.175 | \n", "0.869898 | \n", "2.290146 | \n", "528.797580 | \n", "200.860547 | \n", "
6 | \n", "6 | \n", "410696358 | \n", "1.175 | \n", "0.860055 | \n", "2.290641 | \n", "534.849534 | \n", "200.817166 | \n", "
7 | \n", "7 | \n", "410696358 | \n", "1.175 | \n", "0.872584 | \n", "2.316078 | \n", "527.169958 | \n", "198.611623 | \n", "
8 | \n", "8 | \n", "410696358 | \n", "1.175 | \n", "0.865230 | \n", "2.266900 | \n", "531.650492 | \n", "202.920282 | \n", "
9 | \n", "9 | \n", "410696358 | \n", "1.175 | \n", "0.865937 | \n", "2.305180 | \n", "531.216478 | \n", "199.550571 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "10.879534 | \n", "5.507512 | \n", "42.281223 | \n", "83.522286 | \n", "
1 | \n", "1 | \n", "410696358 | \n", "1.175 | \n", "7.985037 | \n", "2.960860 | \n", "57.607749 | \n", "155.360266 | \n", "
2 | \n", "2 | \n", "410696358 | \n", "1.175 | \n", "11.170788 | \n", "2.792554 | \n", "41.178832 | \n", "164.723768 | \n", "
3 | \n", "3 | \n", "410696358 | \n", "1.175 | \n", "11.086721 | \n", "2.931666 | \n", "41.491077 | \n", "156.907375 | \n", "
4 | \n", "4 | \n", "410696358 | \n", "1.175 | \n", "10.727255 | \n", "2.943897 | \n", "42.881427 | \n", "156.255466 | \n", "
5 | \n", "5 | \n", "410696358 | \n", "1.175 | \n", "7.165172 | \n", "2.955973 | \n", "64.199437 | \n", "155.617123 | \n", "
6 | \n", "6 | \n", "410696358 | \n", "1.175 | \n", "7.418792 | \n", "3.115795 | \n", "62.004704 | \n", "147.634867 | \n", "
7 | \n", "7 | \n", "410696358 | \n", "1.175 | \n", "7.775094 | \n", "3.132531 | \n", "59.163272 | \n", "146.846116 | \n", "
8 | \n", "8 | \n", "410696358 | \n", "1.175 | \n", "7.291722 | \n", "2.939524 | \n", "63.085237 | \n", "156.487925 | \n", "
9 | \n", "9 | \n", "410696358 | \n", "1.175 | \n", "6.927933 | \n", "2.878196 | \n", "66.397871 | \n", "159.822333 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "0.662771 | \n", "2.162894 | \n", "694.055729 | \n", "212.678013 | \n", "
1 | \n", "1 | \n", "21562571 | \n", "22.387 | \n", "3.683232 | \n", "3.536478 | \n", "124.890311 | \n", "130.072913 | \n", "
2 | \n", "2 | \n", "19985468 | \n", "24.154 | \n", "4.939962 | \n", "3.484861 | \n", "93.118127 | \n", "131.999530 | \n", "
3 | \n", "3 | \n", "19364324 | \n", "24.929 | \n", "5.524262 | \n", "3.473563 | \n", "83.269038 | \n", "132.428865 | \n", "
4 | \n", "4 | \n", "17011833 | \n", "28.376 | \n", "8.573870 | \n", "3.662094 | \n", "53.651385 | \n", "125.611198 | \n", "
5 | \n", "5 | \n", "16773528 | \n", "28.779 | \n", "9.709417 | \n", "3.655160 | \n", "47.376687 | \n", "125.849486 | \n", "
6 | \n", "6 | \n", "15251112 | \n", "31.652 | \n", "12.199962 | \n", "3.398706 | \n", "37.705035 | \n", "135.345630 | \n", "
7 | \n", "7 | \n", "15156305 | \n", "31.850 | \n", "14.717500 | \n", "3.480614 | \n", "31.255308 | \n", "132.160592 | \n", "
8 | \n", "8 | \n", "14295434 | \n", "33.768 | \n", "29.362271 | \n", "3.468930 | \n", "15.666363 | \n", "132.605731 | \n", "
9 | \n", "9 | \n", "14114077 | \n", "34.202 | \n", "45.618963 | \n", "3.359124 | \n", "10.083526 | \n", "136.940457 | \n", "
10 rows \u00d7 7 columns
\n", "\n", " | Compression level | \n", "Compressed size | \n", "Compression ratio | \n", "Compression time | \n", "OHLC time | \n", "Writing speed (MiB/s) | \n", "OHLC speed (MiB/s) | \n", "
---|---|---|---|---|---|---|---|
0 | \n", "0 | \n", "485063744 | \n", "0.995 | \n", "9.947921 | \n", "3.326485 | \n", "46.240817 | \n", "138.284098 | \n", "
1 | \n", "1 | \n", "21562571 | \n", "22.387 | \n", "4.717685 | \n", "4.090439 | \n", "97.505446 | \n", "112.457371 | \n", "
2 | \n", "2 | \n", "19985468 | \n", "24.154 | \n", "4.840078 | \n", "4.022526 | \n", "95.039793 | \n", "114.356003 | \n", "
3 | \n", "3 | \n", "19364324 | \n", "24.929 | \n", "5.575667 | \n", "3.940279 | \n", "82.501342 | \n", "116.743002 | \n", "
4 | \n", "4 | \n", "17011833 | \n", "28.376 | \n", "8.509122 | \n", "4.047293 | \n", "54.059632 | \n", "113.656216 | \n", "
5 | \n", "5 | \n", "16773528 | \n", "28.779 | \n", "9.763632 | \n", "4.058696 | \n", "47.113615 | \n", "113.336894 | \n", "
6 | \n", "6 | \n", "15251112 | \n", "31.652 | \n", "12.165651 | \n", "3.965459 | \n", "37.811375 | \n", "116.001708 | \n", "
7 | \n", "7 | \n", "15156305 | \n", "31.850 | \n", "14.992578 | \n", "3.990026 | \n", "30.681848 | \n", "115.287469 | \n", "
8 | \n", "8 | \n", "14295434 | \n", "33.768 | \n", "29.675020 | \n", "3.967705 | \n", "15.501253 | \n", "115.936038 | \n", "
9 | \n", "9 | \n", "14114077 | \n", "34.202 | \n", "45.902231 | \n", "4.076327 | \n", "10.021299 | \n", "112.846692 | \n", "
10 rows \u00d7 7 columns
\n", "