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 .IP \[bu]
 176 Minor_Baseball_Standings_XML.dtd
 177 .IP \[bu]
 178 Minor_Baseball_Transactions_XML.dtd
 179 .IP \[bu]
 180 mlbbattingavgxml.dtd
 181 .IP \[bu]
 182 mlbdoublesleadersxml.dtd
 183 .IP \[bu]
 184 MLBGamesPlayedXML.dtd
 185 .IP \[bu]
 186 MLBGIDPXML.dtd
 187 .IP \[bu]
 188 MLBHitByPitchXML.dtd
 189 .IP \[bu]
 190 mlbhitsleadersxml.dtd
 191 .IP \[bu]
 192 mlbhomerunsxml.dtd
 193 .IP \[bu]
 194 MLBHRFreqXML.dtd
 195 .IP \[bu]
 196 MLBIntWalksXML.dtd
 197 .IP \[bu]
 198 MLBKORateXML.dtd
 199 .IP \[bu]
 200 mlbonbasepctxml.dtd
 201 .IP \[bu]
 202 MLBOPSXML.dtd
 203 .IP \[bu]
 204 MLBPlateAppsXML.dtd
 205 .IP \[bu]
 206 mlbrbisxml.dtd
 207 .IP \[bu]
 208 mlbrunsleadersxml.dtd
 209 .IP \[bu]
 210 MLBSacFliesXML.dtd
 211 .IP \[bu]
 212 MLBSacrificesXML.dtd
 213 .IP \[bu]
 214 MLBSBSuccessXML.dtd
 215 .RE
 216 .P
 217 The GameInfo and SportInfo types do not have their own top-level
 218 tables in the database. Instead, their raw XML is stored in either the
 219 \(dqgame_info\(dq or \(dqsport_info\(dq table respectively.
 220
 221 .SH DATABASE SCHEMA
 222 .P
 223 At the top level (with two notable exceptions), we have one table for
 224 each of the XML document types that we import. For example, the
 225 documents corresponding to \fInewsxml.dtd\fR will have a table called
 226 \(dqnews\(dq. All top-level tables contain two important fields,
 227 \(dqxml_file_id\(dq and \(dqtime_stamp\(dq. The former is unique and
 228 prevents us from inserting the same data twice. The time stamp on the
 229 other hand lets us know when the data is old and can be removed. The
 230 database schema make it possible to delete only the outdated top-level
 231 records; all transient children should be removed by triggers.
 232 .P
 233 These top-level tables will often have children. For example, each
 234 news item has zero or more locations associated with it. The child
 235 table will be named <parent>_<children>, which in this case
 236 corresponds to \(dqnews_locations\(dq.
 237 .P
 238 To relate the two, a third table may exist with name
 239 <parent>__<child>. Note the two underscores. This prevents ambiguity
 240 when the child table itself contains underscores. The table joining
 241 \(dqnews\(dq with \(dqnews_locations\(dq is thus called
 242 \(dqnews__news_locations\(dq. This is necessary when the child table
 243 has a unique constraint; we don't want to blindly insert duplicate
 244 records keyed to the parent. Instead we'd like to use the third table
 245 to map an existing child to the new parent.
 246 .P
 247 Where it makes sense, children are kept unique to prevent pointless
 248 duplication. This slows down inserts, and speeds up reads (which are
 249 much more frequent). There is a tradeoff to be made, however. For a
 250 table with a small, fixed upper bound on the number of rows (like
 251 \(dqodds_casinos\(dq), there is great benefit to de-duplication. The
 252 total number of rows stays small, so inserts are still quick, and many
 253 duplicate rows are eliminated.
 254 .P
 255 But, with a table like \(dqodds_games\(dq, the number of games grows
 256 quickly and without bound. It is therefore more beneficial to be able
 257 to delete the old games (through an ON DELETE CASCADE, tied to
 258 \(dqodds\(dq) than it is to eliminate duplication. A table like
 259 \(dqnews_locations\(dq is somewhere in-between. It is hoped that the
 260 unique constraint in the top-level table's \(dqxml_file_id\(dq will
 261 prevent duplication in this case anyway.
 262 .P
 263 The aforementioned exceptions are the \(dqgame_info\(dq and
 264 \(dqsport_info\(dq tables. These tables contain the raw XML for a
 265 number of DTDs that are not handled individually. This is partially
 266 for backwards-compatibility with a legacy implementation, but is
 267 mostly a stopgap due to a lack of resources at the moment. These two
 268 tables (game_info and sport_info) still possess timestamps that allow
 269 us to prune old data.
 270 .P
 271 UML diagrams of the resulting database schema for each XML document
 272 type are provided with the \fBhtsn-import\fR documentation.
 273
 274 .SH XML Schema Oddities
 275 .P
 276 There are a number of problems with the XML on the wire. Even if we
 277 construct the DTDs ourselves, the results are sometimes
 278 inconsistent. Here we document a few of them.
 279
 280 .IP \[bu] 2
 281 Odds_XML.dtd
 282
 283 The <Notes> elements here are supposed to be associated with a set of
 284 <Game> elements, but since the pair
 285 (<Notes>...</Notes><Game>...</Game>) can appear zero or more times,
 286 this leads to ambiguity in parsing. We therefore ignore the notes
 287 entirely (although a hack is employed to facilitate parsing).
 288
 289 .IP \[bu]
 290 weatherxml.dtd
 291
 292 There appear to be two types of weather documents; the first has
 293 <listing> contained within <forecast> and the second has <forecast>
 294 contained within <listing>. While it would be possible to parse both,
 295 it would greatly complicate things. The first form is more common, so
 296 that's all we support for now.
 297
 298 .SH OPTIONS
 299
 300 .IP \fB\-\-backend\fR,\ \fB\-b\fR
 301 The RDBMS backend to use. Valid choices are \fISqlite\fR and
 302 \fIPostgres\fR. Capitalization is important, sorry.
 303
 304 Default: Sqlite
 305
 306 .IP \fB\-\-connection-string\fR,\ \fB\-c\fR
 307 The connection string used for connecting to the database backend
 308 given by the \fB\-\-backend\fR option. The default is appropriate for
 309 the \fISqlite\fR backend.
 310
 311 Default: \(dq:memory:\(dq
 312
 313 .IP \fB\-\-log-file\fR
 314 If you specify a file here, logs will be written to it (possibly in
 315 addition to syslog). Can be either a relative or absolute path. It
 316 will not be auto-rotated; use something like logrotate for that.
 317
 318 Default: none
 319
 320 .IP \fB\-\-log-level\fR
 321 How verbose should the logs be? We log notifications at four levels:
 322 DEBUG, INFO, WARN, and ERROR. Specify the \(dqmost boring\(dq level of
 323 notifications you would like to receive (in all-caps); more
 324 interesting notifications will be logged as well. The debug output is
 325 extremely verbose and will not be written to syslog even if you try.
 326
 327 Default: INFO
 328
 329 .IP \fB\-\-remove\fR,\ \fB\-r\fR
 330 Remove successfully processed files. If you enable this, you can see
 331 at a glance which XML files are not being processed, because they're
 332 all that should be left.
 333
 334 Default: disabled
 335
 336 .IP \fB\-\-syslog\fR,\ \fB\-s\fR
 337 Enable logging to syslog. On Windows this will attempt to communicate
 338 (over UDP) with a syslog daemon on localhost, which will most likely
 339 not work.
 340
 341 Default: disabled
 342
 343 .SH CONFIGURATION FILE
 344 .P
 345 Any of the command-line options mentioned above can be specified in a
 346 configuration file instead. We first look for \(dqhtsn-importrc\(dq in
 347 the system configuration directory. We then look for a file named
 348 \(dq.htsn-importrc\(dq in the user's home directory. The latter will
 349 override the former.
 350 .P
 351 The user's home directory is simply $HOME on Unix; on Windows it's
 352 wherever %APPDATA% points. The system configuration directory is
 353 determined by Cabal; the \(dqsysconfdir\(dq parameter during the
 354 \(dqconfigure\(dq step is used.
 355 .P
 356 The file's syntax is given by examples in the htsn-importrc.example file
 357 (included with \fBhtsn-import\fR).
 358 .P
 359 Options specified on the command-line override those in either
 360 configuration file.
 361
 362 .SH EXAMPLES
 363 .IP \[bu] 2
 364 Import newsxml.xml into a preexisting sqlite database named \(dqfoo.sqlite3\(dq:
 365
 366 .nf
 367 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 368 .I "              test/xml/newsxml.xml"
 369 Successfully imported test/xml/newsxml.xml.
 370 Imported 1 document(s) total.
 371 .fi
 372 .IP \[bu]
 373 Repeat the previous example, but delete newsxml.xml afterwards:
 374
 375 .nf
 376 .I $ htsn-import --connection-string='foo.sqlite3' \\\\
 377 .I "              --remove test/xml/newsxml.xml"
 378 Successfully imported test/xml/newsxml.xml.
 379 Imported 1 document(s) total.
 380 Removed processed file test/xml/newsxml.xml.
 381 .fi
 382 .IP \[bu]
 383 Use a Postgres database instead of the default Sqlite. This assumes
 384 that you have a database named \(dqhtsn\(dq accessible to user
 385 \(dqpostgres\(dq locally:
 386
 387 .nf
 388 .I $ htsn-import --connection-string='dbname=htsn user=postgres' \\\\
 389 .I "              --backend=Postgres test/xml/newsxml.xml"
 390 Successfully imported test/xml/newsxml.xml.
 391 Imported 1 document(s) total.
 392 .fi
 393
 394 .SH BUGS
 395
 396 .P
 397 Send bugs to michael@orlitzky.com.