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OSCAR 23.01

OSCAR 23.01 is the January 2023 version of the OSCAR Corpus based on the November/December 2022 dump of Common Crawl. While being quite similar to OSCAR 22.01, it contains several new features, including KenLM-based adult content detection, precomputed Locality-Sensitive Hashes for near deduplication, and blocklist-based categories. OSCAR 23.01 has also moved from gzip to Zstandard compression. You might already have zstd installed on your system, but if not, please check the Zstandard website for installation instructions.

Tip

OSCAR 23.01 is similar to OSCAR 22.01. As such, please also check out the documentation for OSCAR 22.01 if you need detailed information about metadata.

Access

Note

If you already have access to the corpus, there's nothing to do! Go up in the file hierarchy on the link you've been given, and you should find the new corpus.

Access to the OSCAR Corpus changes depending on your status. More info on our dedicated page.

Getting access

New Features

Categories

OSCAR 22.01 leveraged the UT1 Blocklists project to attempt to classify some adult content present in OSCAR. The OSCAR 23.01 pipeline iterated on this to include all of the blocklists provided by UT1.

Warning

The UT1 Blocklists page lists all the categories along with a short description. We strongly encourage you to read the descriptions if you plan on using them. Please also note that these descriptions are in French. We're working on an English translation of them.

Note

A document can belong to multiple categories.

These categories are in a field that is at this path: metadata.categories.

Example

{
    "content":"foo",
    "metadata": {
        // ...
        "categories": ["blog", "news"],
        // ...
    }
    // ...
}

KenLM-based Adult Content Filtering

For a select number of subcorpora, a measure of perplexity has been added. This perplexity comes from a KenLM model trained on harmful content, previously gathered by using the adult annotation in OSCAR 22.01. In other terms, the lower it is, the more likely a given document contains harmful/adult content.

Danger

This feature can be considered as unstable/unsafe, since we also want to evaluate its impact on particular issues.

As such, we do not provide a boolean value indicating if a given document can be harmful/adult content, but rather the raw perplexity. We have found a threshold that works well in English, but encourage you to experiment with it and to report back your findings.

Locality Sensitive Hashing

We use TLSH to compute a hash for each document.

Locality sensitive hashing is a hashing method that computes similar hashes for similar documents.

This can be used to do both exact- and near- deduplication. Same documents have same hashes (the reverse might not be true). So you only need to check for identity amongst documents with identical hashes. TLSH hashes can be compared to yield a distance metric. According to the original paper, a cutoff of < 40 yields a false positive rate of 0.07% and a detect rate of 49.6%, while a cutoff of < 100 yields a FP rate of 6.43% and detect rate of 94.5%. You should choose a value that meets your purposes.

The above is true for the default version of TLSH which is used in packages such as py-tlsh. OSCAR 23.01 uses a TLSH with a hyperparameter of 256 buckets (Full hash), and 3 byte checksums (collision rate : 1 in 5800) instead of 1 byte checksums (collision rate : 1 in 24).

If you would like to use py-tlsh, follow these instructions (You need CMake installed to perform the necessary modifications and build): 

# download py-tlsh source package
pip download python-tlsh
# unpack the source tar.gz and enter the directory
tar -xvf python-tlsh-4.5.0.tar.gz && cd python-tlsh-4.5.0
# run the following command to implement the changes
# alternatively, you can use vi or a text editor
# change TLSH_BUCKETS_128 into TLSH_BUCKETS_256 and change TLSH_CHECKSUM_1B into TLSH_CHECKSUM_3B
sed -i 's/set(TLSH_BUCKETS_128 1)/set(TLSH_BUCKETS_256 1)/g; s/set(TLSH_CHECKSUM_1B 1)/set(TLSH_CHECKSUM_3B 1)/g' CMakeLists.txt

# build and activate pip venv if not already done
# python3 -m venv ~/.venv
source ~/.venv/bin/activate
# build and install the new py-tlsh
python3 setup.py install

Hashes are at metadata.tlsh.

Minor changes

  • metadata.annotations has been renamed metadata.quality_warnings, and only contains length based quality warnings (see the OSCAR 2201 documentation for details).
  • Some language tags have changed to better respect the BCP47:
    • als has become gsw. Previously, als was erroneously used as the tag for Alemannic/Swiss German, whereas it is the tag for Tosk Albanian.
    • eml has become x-eml. The eml tag is deprecated and as such has been replaced by a private tag (x-eml).

Layout

{
   "content":"English sentence\nphrase en français\n????????????", // (1)
   "warc_headers":{ // (2)
      "warc-identified-content-language":"fra,eng",
      "warc-target-uri":"https://fr.wikipedia.org/wiki/...",
      "warc-record-id":"<urn:uuid:29eaa920-d299-4b1d-b687-c72bd8d68116>",
      "warc-type":"conversion",
      "content-length":"35298", // (3)
      "warc-refers-to":"<urn:uuid:39e42055-0d94-4e45-9c6c-9e7056635d64>",
      "warc-block-digest":"sha1:WFH2A5WHCS2H365GIAFYQPI7UOAMFGHB", // (3)
      "warc-date":"2022-11-26T09:45:47Z",
      "content-type":"text/plain"
   },
   "metadata":{
      "identification":{ // (4)
         "label":"fr",
         "prob":0.8938327
      },
      "harmful_pp":4063.1814, // (5)
      "tlsh":"tlsh:T125315FF2B6088901EEA097015DB39B4600B...", // (6)
      "quality_warnings":[ // (7)
         "short_sentences",
         "header",
         "footer"
      ],
      "categories":[ // (8)
         "examen_pix",
         "liste_bu"
      ],
      "sentence_identifications":[ // (9)
         {
            "label":"fr",
            "prob":0.99837273
         },
         {
            "label":"en",
            "prob":0.9992377
         },
         null
      ]
   }
}

Some important notes:

  1. Newline-separated content.
  2. Headers from the crawled dumps are left untouched. See the WARC specification for more info.
  3. Since warc_headers are copied and content can be altered by Ungoliant at generation stage, content-length and warc-block-digest can be different from actual values.
  4. Document-level identification. Computation details can be found on the OSCAR 22.01 paper.
  5. Perplexity of the document, computed using a KenLM model trained on harmful content. See this pre-print for more info. The lower this number is, the higher the probability that it will contain harmful or adult content. This annotation will be changed from harmful_pp to harmful_pplin future releases.
  6. Locality Sensitive Hash of the documents' content, using TLSH. Useful for both exact and near deduplication.
  7. (Corresponds to annotations pre-23.01) Potential quality warnings. Based on content/sentence length. See [OSCAR 22.01 paper for more info.
  8. Blocklist-based categories. Uses the UT1 Blocklist, plus custom additions. Please refer to the UT1 website for categories description. Note that the categories are in French.
  9. Sentence-level identifications. A null value means no identification with a good enough threshold (>0.8 on 23.01).

Language table

Code Language # docs # words Content Length :
0 af Afrikaans 23,994 6,217,024 37.2 MB
1 sq Albanian 1,342,790 462,694,599 3.2 GB
2 am Amharic 119,434 40,262,809 512.9 MB
3 ar Arabic 25,012,116 10,081,452,882 110.7 GB
4 an Aragonese 34 264 11.0 kB
5 hy Armenian 1,056,974 336,045,041 4.9 GB
6 as Assamese 89,542 24,395,215 412.1 MB
7 ast Asturian 440 10,917 74.1 kB
8 av Avaric 44 1,073 18.6 kB
9 az Azerbaijani 1,159,994 316,850,330 3.0 GB
10 bn Bangla 3,474,086 1,092,983,765 19.1 GB
11 ba Bashkir 128,248 26,036,637 363.7 MB
12 eu Basque 678,474 136,672,615 1.2 GB
13 be Belarusian 445,612 164,729,607 2.3 GB
14 bh Bihari languages 48 507 6.8 kB
15 bpy Bishnupriya 2,346 346,947 5.4 MB
16 bs Bosnian 20 395 3.0 kB
17 br Breton 36,338 4,759,407 31.4 MB
18 bg Bulgarian 8,933,998 3,635,273,738 44.1 GB
19 my Burmese 430,276 82,433,836 3.0 GB
20 ca Catalan 6,953,898 2,240,460,836 15.3 GB
21 ceb Cebuano 16,174 6,263,404 41.1 MB
22 ckb Central Kurdish 182,508 61,334,746 772.9 MB
23 ce Chechen 11,686 1,051,752 13.9 MB
24 zh Chinese 138,478,270 44,378,380,161 1.4 TB
25 cv Chuvash 16,652 3,039,925 42.3 MB
26 kw Cornish 8 80 432 Bytes
27 hr Croatian 31,808 3,542,961 26.5 MB
28 cs Czech 34,859,632 9,717,378,559 77.0 GB
29 da Danish 7,214,338 2,217,634,340 14.8 GB
30 dv Divehi 77,060 10,655,359 200.1 MB
31 nl Dutch 72,552,688 19,564,553,306 135.0 GB
32 mhr Eastern Mari 9,502 1,615,215 22.9 MB
33 arz Egyptian Arabic 3,958 385,511 3.7 MB
34 en English 1,235,510,986 523,869,288,690 3.4 TB
35 eo Esperanto 226,924 67,774,923 474.8 MB
36 et Estonian 3,601,904 938,296,892 8.0 GB
37 tl Filipino 250,558 110,560,444 719.2 MB
38 fi Finnish 14,471,710 4,198,143,883 41.1 GB
39 fr French 158,334,998 62,127,088,294 430.5 GB
40 gl Galician 248,762 38,345,625 255.7 MB
41 ka Georgian 1,343,036 373,935,158 8.4 GB
42 de German 206,598,430 73,848,586,648 594.7 GB
43 gom Goan Konkani 398 121,035 2.3 MB
44 el Greek 20,282,864 7,691,622,692 95.7 GB
45 gn Guarani 14 260 2.2 kB
46 gu Gujarati 425,552 417,001,705 5.6 GB
47 ht Haitian Creole 2 20,671 93.1 kB
48 he Hebrew 3,997,888 1,697,158,891 18.0 GB
49 hi Hindi 5,514,454 2,475,605,444 32.6 GB
50 hu Hungarian 21,349,372 16,013,364,289 150.1 GB
51 is Icelandic 1,210,232 294,471,539 2.2 GB
52 io Ido 224 2,598 16.1 kB
53 ilo Iloko 144 4,411 28.0 kB
54 id Indonesian 7,109,778 3,228,020,221 23.4 GB
55 ia Interlingua 34 9,384 33.5 kB
56 ie Interlingue 2 0 881 Bytes
57 ga Irish 29,894 9,054,923 63.2 MB
58 it Italian 89,021,606 36,327,274,203 259.4 GB
59 ja Japanese 94,236,404 4,401,059,165 181.2 GB
60 jv Javanese 172 3,286 25.7 kB
61 xal Kalmyk 2 27 315 Bytes
62 kn Kannada 448,500 124,924,350 2.6 GB
63 krc Karachay-Balkar 496 8,385 122.4 kB
64 kk Kazakh 677,622 214,679,857 3.3 GB
65 km Khmer 450,660 59,880,231 3.2 GB
66 kv Komi 460 5,909 70.3 kB
67 ko Korean 15,147,698 3,435,866,935 38.1 GB
68 ku Kurdish 80,338 25,921,607 174.1 MB
69 ky Kyrgyz 144,288 32,062,783 489.3 MB
70 lo Lao 118,374 10,659,203 472.1 MB
71 la Latin 14,384 307,865 2.0 MB
72 lv Latvian 2,435,882 845,459,899 7.4 GB
73 lez Lezghian 676 60,634 856.6 kB
74 li Limburgish 6 169 1.4 kB
75 lt Lithuanian 5,182,028 1,674,362,574 14.5 GB
76 jbo Lojban 572 312,315 1.5 MB
77 lmo Lombard 112 3,269 21.0 kB
78 nds Low German 5,248 1,612,175 10.7 MB
79 dsb Lower Sorbian 8 84 664 Bytes
80 lb Luxembourgish 18,090 2,514,838 18.4 MB
81 mk Macedonian 1,063,298 389,344,425 4.7 GB
82 mai Maithili 46 467 6.8 kB
83 mg Malagasy 10,830 1,416,430 11.2 MB
84 ms Malay 11,500 238,477 2.6 MB
85 ml Malayalam 800,936 236,597,838 5.8 GB
86 mt Maltese 5,180 149,886 1.3 MB
87 mr Marathi 729,578 252,706,331 4.5 GB
88 mzn Mazanderani 384 16,115 169.2 kB
89 min Minangkabau 2,436 305,589 3.8 MB
90 xmf Mingrelian 7,318 283,316 6.1 MB
91 mwl Mirandese 4 54 423 Bytes
92 mn Mongolian 1,061,710 454,350,415 5.8 GB
93 multi Multilingual 2,948,202 1,251,676,406 11.9 GB
94 nah Nahuatl languages 38 279 2.4 kB
95 ne Nepali 1,152,156 278,901,036 4.9 GB
96 new Newari 1,996 229,703 4.0 MB
97 no Norwegian 2,797,378 373,160,033 2.6 GB
98 nn Norwegian Nynorsk 19,470 575,518 3.7 MB
99 oc Occitan 920 34,701 405.0 kB
100 or Odia 158,426 31,963,340 543.1 MB
101 os Ossetic 8,628 3,935,964 50.7 MB
102 ps Pashto 87,408 30,196,179 261.6 MB
103 fa Persian 23,813,882 9,609,206,698 93.2 GB
104 pms Piedmontese 2,524 510,087 3.1 MB
105 pl Polish 57,184,826 18,073,705,588 147.1 GB
106 pt Portuguese 36,062,800 15,172,557,311 105.0 GB
107 pa Punjabi 222,058 104,235,418 1.4 GB
108 qu Quechua 2 13 143 Bytes
109 ro Romanian 11,985,668 6,302,600,833 45.6 GB
110 bxr Russia Buriat 72 698 8.2 kB
111 ru Russian 194,143,422 78,032,029,344 1.1 TB
112 sah Sakha 17,566 4,288,051 68.8 MB
113 sa Sanskrit 16,802 2,479,345 56.3 MB
114 gd Scottish Gaelic 776 18,458 146.1 kB
115 sr Serbian 1,677,896 632,781,822 7.7 GB
116 sh Serbian (Latin) 3,214 166,517 816.4 kB
117 sd Sindhi 48,566 14,667,207 131.6 MB
118 si Sinhala 301,066 172,755,385 2.6 GB
119 sk Slovak 8,931,784 2,704,716,280 21.5 GB
120 sl Slovenian 1,112,560 192,816,743 1.4 GB
121 so Somali 6 51 503 Bytes
122 azb South Azerbaijani 26,364 2,029,729 28.4 MB
123 es Spanish 153,574,556 63,388,237,965 429.9 GB
124 su Sundanese 18 258 2.0 kB
125 sw Swahili 1,664 164,459 1.0 MB
126 sv Swedish 21,891,348 6,993,719,601 50.0 GB
127 gsw Swiss German 342 34,328 232.7 kB
128 tg Tajik 144,932 76,987,285 1.0 GB
129 ta Tamil 1,638,238 738,824,392 15.8 GB
130 tt Tatar 262,654 59,253,765 833.8 MB
131 te Telugu 644,712 201,575,815 3.9 GB
132 th Thai 14,845,900 2,224,483,018 92.0 GB
133 bo Tibetan 62,352 6,062,558 531.6 MB
134 tr Turkish 26,654,330 8,290,890,087 73.7 GB
135 tk Turkmen 4,576 325,786 3.3 MB
136 uk Ukrainian 10,059,992 3,183,842,018 44.7 GB
137 x-eml Emiliano-Romagnol 4 329 1.8 kB
138 hsb Upper Sorbian 402 15,827 123.2 kB
139 ur Urdu 887,004 434,023,273 3.8 GB
140 ug Uyghur 51,304 14,659,554 219.8 MB
141 uz Uzbek 15,806 1,665,960 15.3 MB
142 vi Vietnamese 33,933,994 22,424,984,210 140.8 GB
143 vo Volapük 896 49,968 371.9 kB
144 wa Walloon 390 6,347 34.3 kB
145 war Waray 1,494 19,665 126.8 kB
146 cy Welsh 151,512 52,250,043 333.0 MB
147 fy Western Frisian 45,458 9,885,788 70.4 MB
148 mrj Western Mari 496 60,180 765.8 kB
149 pnb Western Panjabi 12,904 11,844,695 105.8 MB
150 wuu Wu Chinese 136 1,199 26.8 kB
151 yi Yiddish 47,438 14,287,370 171.7 MB
152 yo Yoruba 128 2,396 16.6 kB