doc/man1/htsn-import.1

   1 .TH htsn-import 1
   2
   3 .SH NAME
   4 htsn-import \- Import XML files from The Sports Network into an RDBMS.
   5
   6 .SH SYNOPSIS
   7
   8 \fBhtsn-import\fR [OPTIONS] [FILES]
   9
  10 .SH DESCRIPTION
  11 .P
  12 The Sports Network <http://www.sportsnetwork.com/> offers an XML feed
  13 containing various sports news and statistics. Our sister program
  14 \fBhtsn\fR is capable of retrieving the feed and saving the individual
  15 XML documents contained therein. But what to do with them?
  16 .P
  17 The purpose of \fBhtsn-import\fR is to take these XML documents and
  18 get them into something we can use, a relational database management
  19 system (RDBMS), otherwise known as a SQL database. The structure of
  20 relational database, is, well, relational, and the feed XML is not. So
  21 there is some work to do before the data can be imported into the
  22 database.
  23 .P
  24 First, we must parse the XML. Each supported document type (see below)
  25 has a full pickle/unpickle implementation (\(dqpickle\(dq is simply a
  26 synonym for serialize here). That means that we parse the entire
  27 document into a data structure, and if we pickle (serialize) that data
  28 structure, we get the exact same XML document tha we started with.
  29 .P
  30 This is important for two reasons. First, it serves as a second level
  31 of validation. The first validation is performed by the XML parser,
  32 but if that succeeds and unpicking fails, we know that something is
  33 fishy. Second, we don't ever want to be surprised by some new element
  34 or attribute showing up in the XML. The fact that we can unpickle the
  35 whole thing now means that we won't be surprised in the future.
  36 .P
  37 The aforementioned feature is especially important because we
  38 automatically migrate the database schema every time we import a
  39 document. If you attempt to import a \(dqnewsxml.dtd\(dq document, all
  40 database objects relating to the news will be created if they do not
  41 exist. We don't want the schema to change out from under us without
  42 warning, so it's important that no XML be parsed that would result in
  43 a different schema than we had previously. Since we can
  44 pickle/unpickle everything already, this should be impossible.
  45
  46 .SH SUPPORTED DOCUMENT TYPES
  47 .P
  48 The XML document types obtained from the feed are uniquely identified
  49 by their DTDs. We currently support documents with the following DTDs:
  50 .IP \[bu] 2
  51 AutoRacingResultsXML.dtd
  52 .IP \[bu]
  53 Auto_Racing_Schedule_XML.dtd
  54 .IP \[bu]
  55 Heartbeat.dtd
  56 .IP \[bu]
  57 Injuries_Detail_XML.dtd
  58 .IP \[bu]
  59 injuriesxml.dtd
  60 .IP \[bu]
  61 newsxml.dtd
  62 .IP \[bu]
  63 Odds_XML.dtd
  64 .IP \[bu]
  65 scoresxml.dtd
  66 .IP \[bu]
  67 weatherxml.dtd
  68 .IP \[bu]
  69 GameInfo
  70 .RS
  71 .IP \[bu]
  72 CBASK_Lineup_XML.dtd
  73 .IP \[bu]
  74 cbaskpreviewxml.dtd
  75 .IP \[bu]
  76 cflpreviewxml.dtd
  77 .IP \[bu]
  78 Matchup_NBA_NHL_XML.dtd
  79 .IP \[bu]
  80 MLB_Gaming_Matchup_XML.dtd
  81 .IP \[bu]
  82 MLB_Lineup_XML.dtd
  83 .IP \[bu]
  84 MLB_Matchup_XML.dtd
  85 .IP \[bu]
  86 MLS_Preview_XML.dtd
  87 .IP \[bu]
  88 mlbpreviewxml.dtd
  89 .IP \[bu]
  90 NBA_Gaming_Matchup_XML.dtd
  91 .IP \[bu]
  92 NBA_Playoff_Matchup_XML.dtd
  93 .IP \[bu]
  94 NBALineupXML.dtd
  95 .IP \[bu]
  96 nbapreviewxml.dtd
  97 .IP \[bu]
  98 NCAA_FB_Preview_XML.dtd
  99 .IP \[bu]
 100 NFL_NCAA_FB_Matchup_XML.dtd
 101 .IP \[bu]
 102 nflpreviewxml.dtd
 103 .IP \[bu]
 104 nhlpreviewxml.dtd
 105 .IP \[bu]
 106 recapxml.dtd
 107 .IP \[bu]
 108 WorldBaseballPreviewXML.dtd
 109 .RE
 110 .IP \[bu]
 111 SportInfo
 112 .RS
 113 .IP \[bu]
 114 CBASK_3PPctXML.dtd
 115 .IP \[bu]
 116 Cbask_All_Tourn_Teams_XML.dtd
 117 .IP \[bu]
 118 CBASK_AssistsXML.dtd
 119 .IP \[bu]
 120 Cbask_Awards_XML.dtd
 121 .IP \[bu]
 122 CBASK_BlocksXML.dtd
 123 .IP \[bu]
 124 Cbask_Conf_Standings_XML.dtd
 125 .IP \[bu]
 126 Cbask_DivII_III_Indv_Stats_XML.dtd
 127 .IP \[bu]
 128 Cbask_DivII_Team_Stats_XML.dtd
 129 .IP \[bu]
 130 Cbask_DivIII_Team_Stats_XML.dtd
 131 .IP \[bu]
 132 CBASK_FGPctXML.dtd
 133 .IP \[bu]
 134 CBASK_FoulsXML.dtd
 135 .IP \[bu]
 136 CBASK_FTPctXML.dtd
 137 .IP \[bu]
 138 Cbask_Indv_Scoring_XML.dtd
 139 .IP \[bu]
 140 CBASK_MinutesXML.dtd
 141 .IP \[bu]
 142 Cbask_Polls_XML.dtd
 143 .IP \[bu]
 144 CBASK_ReboundsXML.dtd
 145 .IP \[bu]
 146 CBASK_ScoringLeadersXML.dtd
 147 .IP \[bu]
 148 Cbask_Team_ThreePT_Made_XML.dtd
 149 .IP \[bu]
 150 Cbask_Team_ThreePT_PCT_XML.dtd
 151 .IP \[bu]
 152 Cbask_Team_Win_Pct_XML.dtd
 153 .IP \[bu]
 154 Cbask_Top_Twenty_Five_XML.dtd
 155 .IP \[bu]
 156 CBASK_TopTwentyFiveResult_XML.dtd
 157 .IP \[bu]
 158 Cbask_Tourn_Awards_XML.dtd
 159 .IP \[bu]
 160 Cbask_Tourn_Champs_XML.dtd
 161 .IP \[bu]
 162 Cbask_Tourn_Indiv_XML.dtd
 163 .IP \[bu]
 164 Cbask_Tourn_Leaders_XML.dtd
 165 .IP \[bu]
 166 Cbask_Tourn_MVP_XML.dtd
 167 .IP \[bu]
 168 Cbask_Tourn_Records_XML.dtd
 169 .IP \[bu]
 170 LeagueScheduleXML.dtd
 171 .IP \[bu]
 172 minorscoresxml.dtd
 173 .IP \[bu]
 174 Minor_Baseball_League_Leaders_XML.dtd
 175 .RE
 176 .P
 177 The GameInfo and SportInfo types do not have their own top-level
 178 tables in the database. Instead, their raw XML is stored in either the
 179 \(dqgame_info\(dq or \(dqsport_info\(dq table respectively.
 180
 181 .SH DATABASE SCHEMA
 182 .P
 183 At the top level (with two notable exceptions), we have one table for
 184 each of the XML document types that we import. For example, the
 185 documents corresponding to \fInewsxml.dtd\fR will have a table called
 186 \(dqnews\(dq. All top-level tables contain two important fields,
 187 \(dqxml_file_id\(dq and \(dqtime_stamp\(dq. The former is unique and
 188 prevents us from inserting the same data twice. The time stamp on the
 189 other hand lets us know when the data is old and can be removed. The
 190 database schema make it possible to delete only the outdated top-level
 191 records; all transient children should be removed by triggers.
 192 .P
 193 These top-level tables will often have children. For example, each
 194 news item has zero or more locations associated with it. The child
 195 table will be named <parent>_<children>, which in this case
 196 corresponds to \(dqnews_locations\(dq.
 197 .P
 198 To relate the two, a third table may exist with name
 199 <parent>__<child>. Note the two underscores. This prevents ambiguity
 200 when the child table itself contains underscores. The table joining
 201 \(dqnews\(dq with \(dqnews_locations\(dq is thus called
 202 \(dqnews__news_locations\(dq. This is necessary when the child table
 203 has a unique constraint; we don't want to blindly insert duplicate
 204 records keyed to the parent. Instead we'd like to use the third table
 205 to map an existing child to the new parent.
 206 .P
 207 Where it makes sense, children are kept unique to prevent pointless
 208 duplication. This slows down inserts, and speeds up reads (which are
 209 much more frequent). There is a tradeoff to be made, however. For a
 210 table with a small, fixed upper bound on the number of rows (like
 211 \(dqodds_casinos\(dq), there is great benefit to de-duplication. The
 212 total number of rows stays small, so inserts are still quick, and many
 213 duplicate rows are eliminated.
 214 .P
 215 But, with a table like \(dqodds_games\(dq, the number of games grows
 216 quickly and without bound. It is therefore more beneficial to be able
 217 to delete the old games (through an ON DELETE CASCADE, tied to
 218 \(dqodds\(dq) than it is to eliminate duplication. A table like
 219 \(dqnews_locations\(dq is somewhere in-between. It is hoped that the
 220 unique constraint in the top-level table's \(dqxml_file_id\(dq will
 221 prevent duplication in this case anyway.
 222 .P
 223 The aforementioned exceptions are the \(dqgame_info\(dq and
 224 \(dqsport_info\(dq tables. These tables contain the raw XML for a
 225 number of DTDs that are not handled individually. This is partially
 226 for backwards-compatibility with a legacy implementation, but is
 227 mostly a stopgap due to a lack of resources at the moment. These two
 228 tables (game_info and sport_info) still possess timestamps that allow
 229 us to prune old data.
 230 .P
 231 UML diagrams of the resulting database schema for each XML document
 232 type are provided with the \fBhtsn-import\fR documentation.
 233
 234 .SH XML Schema Oddities
 235 .P
 236 There are a number of problems with the XML on the wire. Even if we
 237 construct the DTDs ourselves, the results are sometimes
 238 inconsistent. Here we document a few of them.
 239
 240 .IP \[bu] 2
 241 Odds_XML.dtd
 242
 243 The <Notes> elements here are supposed to be associated with a set of
 244 <Game> elements, but since the pair
 245 (<Notes>...</Notes><Game>...</Game>) can appear zero or more times,
 246 this leads to ambiguity in parsing. We therefore ignore the notes
 247 entirely (although a hack is employed to facilitate parsing).
 248
 249 .IP \[bu]
 250 weatherxml.dtd
 251
 252 There appear to be two types of weather documents; the first has
 253 <listing> contained within <forecast> and the second has <forecast>
 254 contained within <listing>. While it would be possible to parse both,
 255 it would greatly complicate things. The first form is more common, so
 256 that's all we support for now.
 257
 258 .SH OPTIONS
 259
 260 .IP \fB\-\-backend\fR,\ \fB\-b\fR
 261 The RDBMS backend to use. Valid choices are \fISqlite\fR and
 262 \fIPostgres\fR. Capitalization is important, sorry.
 263
 264 Default: Sqlite
 265
 266 .IP \fB\-\-connection-string\fR,\ \fB\-c\fR
 267 The connection string used for connecting to the database backend
 268 given by the \fB\-\-backend\fR option. The default is appropriate for
 269 the \fISqlite\fR backend.
 270
 271 Default: \(dq:memory:\(dq
 272
 273 .IP \fB\-\-log-file\fR
 274 If you specify a file here, logs will be written to it (possibly in
 275 addition to syslog). Can be either a relative or absolute path. It
 276 will not be auto-rotated; use something like logrotate for that.
 277
 278 Default: none
 279
 280 .IP \fB\-\-log-level\fR
 281 How verbose should the logs be? We log notifications at four levels:
 282 DEBUG, INFO, WARN, and ERROR. Specify the \(dqmost boring\(dq level of
 283 notifications you would like to receive (in all-caps); more
 284 interesting notifications will be logged as well. The debug output is
 285 extremely verbose and will not be written to syslog even if you try.
 286
 287 Default: INFO
 288
 289 .IP \fB\-\-remove\fR,\ \fB\-r\fR
 290 Remove successfully processed files. If you enable this, you can see
 291 at a glance which XML files are not being processed, because they're
 292 all that should be left.
 293
 294 Default: disabled
 295
 296 .IP \fB\-\-syslog\fR,\ \fB\-s\fR
 297 Enable logging to syslog. On Windows this will attempt to communicate
 298 (over UDP) with a syslog daemon on localhost, which will most likely
 299 not work.
 300
 301 Default: disabled
 302
 303 .SH CONFIGURATION FILE
 304 .P
 305 Any of the command-line options mentioned above can be specified in a
 306 configuration file instead. We first look for \(dqhtsn-importrc\(dq in
 307 the system configuration directory. We then look for a file named
 308 \(dq.htsn-importrc\(dq in the user's home directory. The latter will
 309 override the former.
 310 .P
 311 The user's home directory is simply $HOME on Unix; on Windows it's
 312 wherever %APPDATA% points. The system configuration directory is
 313 determined by Cabal; the \(dqsysconfdir\(dq parameter during the
 314 \(dqconfigure\(dq step is used.
 315 .P
 316 The file's syntax is given by examples in the htsn-importrc.example file
 317 (included with \fBhtsn-import\fR).
 318 .P
 319 Options specified on the command-line override those in either
 320 configuration file.
 321
 322 .SH EXAMPLES
 323 .IP \[bu] 2
 324 Import newsxml.xml into a preexisting sqlite database named \(dqfoo.sqlite3\(dq:
 325
 326 .nf
 327 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 328 .I "              test/xml/newsxml.xml"
 329 Successfully imported test/xml/newsxml.xml.
 330 Imported 1 document(s) total.
 331 .fi
 332 .IP \[bu]
 333 Repeat the previous example, but delete newsxml.xml afterwards:
 334
 335 .nf
 336 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 337 .I "              --remove test/xml/newsxml.xml"
 338 Successfully imported test/xml/newsxml.xml.
 339 Imported 1 document(s) total.
 340 Removed processed file test/xml/newsxml.xml.
 341 .fi
 342 .IP \[bu]
 343 Use a Postgres database instead of the default Sqlite. This assumes
 344 that you have a database named \(dqhtsn\(dq accessible to user
 345 \(dqpostgres\(dq locally:
 346
 347 .nf
 348 .I $ htsn-import --connection-string='dbname=htsn user=postgres' \\\\
 349 .I "              --backend=Postgres test/xml/newsxml.xml"
 350 Successfully imported test/xml/newsxml.xml.
 351 Imported 1 document(s) total.
 352 .fi
 353
 354 .SH BUGS
 355
 356 .P
 357 Send bugs to michael@orlitzky.com.