Merge pull request ClickHouse#62690 from peter279k/improve_wikistat_data

Add the loading data with cleaning approach

docs/en/getting-started/example-datasets/wikistat.md

@@ -13,7 +13,7 @@ And the presentation: https://presentations.clickhouse.com/fosdem2023/
 Data source: https://dumps.wikimedia.org/other/pageviews/
 
 Getting the list of links:
-```
+``` shell
 for i in {2015..2023}; do
   for j in {01..12}; do
     echo "${i}-${j}" >&2
@@ -24,7 +24,7 @@ done | sort | uniq | tee links.txt
 ```
 
 Downloading the data:
-```
+``` shell
 sed -r 's!pageviews-([0-9]{4})([0-9]{2})[0-9]{2}-[0-9]+\.gz!https://dumps.wikimedia.org/other/pageviews/\1/\1-\2/\0!' \
   links.txt | xargs -P3 wget --continue
 ```
@@ -40,16 +40,15 @@ CREATE TABLE wikistat
     project LowCardinality(String),
     subproject LowCardinality(String),
     path String CODEC(ZSTD(3)),
-    hits UInt64 CODEC(ZSTD(3)),
-    size UInt64 CODEC(ZSTD(3))
+    hits UInt64 CODEC(ZSTD(3))
 )
 ENGINE = MergeTree
 ORDER BY (path, time);
 ```
 
 Loading the data:
 
-```
+``` shell
 clickhouse-local --query "
   WITH replaceRegexpOne(_path, '^.+pageviews-(\\d{4})(\\d{2})(\\d{2})-(\\d{2})(\\d{2})(\\d{2}).gz$', '\1-\2-\3 \4-\5-\6')::DateTime AS time, 
        extractGroups(line, '^([^ \\.]+)(\\.[^ ]+)? +([^ ]+) +(\\d+) +(\\d+)$') AS values
@@ -58,9 +57,27 @@ clickhouse-local --query "
     values[1] AS project,
     values[2] AS subproject,
     values[3] AS path,
-    (values[4])::UInt64 AS hits,
-    (values[5])::UInt64 AS size
+    (values[4])::UInt64 AS hits
   FROM file('pageviews*.gz', LineAsString)
   WHERE length(values) = 5 FORMAT Native
 " | clickhouse-client --query "INSERT INTO wikistat FORMAT Native"
 ```
+
+Or loading the cleaning data:
+
+``` sql
+INSERT INTO wikistat WITH
+    parseDateTimeBestEffort(extract(_file, '^pageviews-([\\d\\-]+)\\.gz$')) AS time,
+    splitByChar(' ', line) AS values,
+    splitByChar('.', values[1]) AS projects
+SELECT
+    time,
+    projects[1] AS project,
+    projects[2] AS subproject,
+    decodeURLComponent(values[2]) AS path,
+    CAST(values[3], 'UInt64') AS hits
+FROM s3(
+    'https://clickhouse-public-datasets.s3.amazonaws.com/wikistat/original/pageviews*.gz',
+    LineAsString)
+WHERE length(values) >= 3
+```