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Remove subselect and use better index.

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The main problem is that we were using an index on fdroid_apk.vercode,
when it should have been using an index on fdroid_apk.appId. There are
thousands of apks which would match based on vercode, but only two or
three which match based on appId. This improves performance of the
calculate-suggested-vercode query from 25,000ms to 100ms.
This commit is contained in:
Peter Serwylo 2017-06-09 14:46:05 +10:00
parent bb96cdeff9
commit de149cf589
2 changed files with 15 additions and 31 deletions
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44
app/src/main/java/org/fdroid/fdroid/data/AppProvider.java
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@ -961,9 +961,9 @@ public class AppProvider extends FDroidProvider {
private void updateSuggestedFromUpstream() {
Utils.debugLog(TAG, "Calculating suggested versions for all NON-INSTALLED apps which specify an upstream version code.");
Utils.Profiler profiler = new Utils.Profiler("UpdateSuggestedApks");
final String apk = getApkTableName();
final String app = getTableName();
final String installed = InstalledAppTable.NAME;
final boolean unstableUpdates = Preferences.get().getUnstableUpdates();
String restrictToStable = unstableUpdates ? "" : (apk + "." + ApkTable.Cols.VERSION_CODE + " <= " + app + "." + Cols.UPSTREAM_VERSION_CODE + " AND ");
@ -974,20 +974,28 @@ public class AppProvider extends FDroidProvider {
// By adding the extra join, and then joining based on the packageId of this inner app table
// and the app table we are updating, we take into account all apks for this app.
// The check apk.sig = COALESCE(installed.sig, apk.sig) would ideally be better written as:
// `installedSig IS NULL OR installedSig = apk.sig`
// however that would require a separate sub query for each `installedSig` which is more
// expensive. Using a COALESCE is a less expressive way to write the same thing with only
// a single subquery.
// Also note that the `installedSig IS NULL` is not because there is a `NULL` entry in the
// installed table (this is impossible), but rather because the subselect above returned
// zero rows.
String updateSql =
"UPDATE " + app + " SET " + Cols.SUGGESTED_VERSION_CODE + " = ( " +
" SELECT MAX( " + apk + "." + ApkTable.Cols.VERSION_CODE + " ) " +
" FROM " + apk +
" JOIN " + app + " AS appForThisApk ON (appForThisApk." + Cols.ROW_ID + " = " + apk + "." + ApkTable.Cols.APP_ID + ") " +
" LEFT JOIN " + installed + " ON (" + installed + "." + InstalledAppTable.Cols.PACKAGE_ID + " = " + app + "." + Cols.PACKAGE_ID + ") " +
" WHERE " +
restrictToSameSigIfInstalled(app, apk) + " AND " +
app + "." + Cols.PACKAGE_ID + " = appForThisApk." + Cols.PACKAGE_ID + " AND " +
apk + "." + ApkTable.Cols.SIGNATURE + " = COALESCE(" + installed + "." + InstalledAppTable.Cols.SIGNATURE + ", " + apk + "." + ApkTable.Cols.SIGNATURE + ") AND " +
restrictToStable +
" ( " + app + "." + Cols.IS_COMPATIBLE + " = 0 OR " + apk + "." + Cols.IS_COMPATIBLE + " = 1 ) ) " +
" WHERE " + Cols.UPSTREAM_VERSION_CODE + " > 0 ";
LoggingQuery.execSQL(db(), updateSql);
profiler.log("Done");
}
/**
@ -1005,47 +1013,23 @@ public class AppProvider extends FDroidProvider {
final String apk = getApkTableName();
final String app = getTableName();
final String installed = InstalledAppTable.NAME;
String updateSql =
"UPDATE " + app + " SET " + Cols.SUGGESTED_VERSION_CODE + " = ( " +
" SELECT MAX( " + apk + "." + ApkTable.Cols.VERSION_CODE + " ) " +
" FROM " + apk +
" JOIN " + app + " AS appForThisApk ON (appForThisApk." + Cols.ROW_ID + " = " + apk + "." + ApkTable.Cols.APP_ID + ") " +
" LEFT JOIN " + installed + " ON (" + installed + "." + InstalledAppTable.Cols.PACKAGE_ID + " = " + app + "." + Cols.PACKAGE_ID + ") " +
" WHERE " +
restrictToSameSigIfInstalled(app, apk) + " AND " +
app + "." + Cols.PACKAGE_ID + " = appForThisApk." + Cols.PACKAGE_ID + " AND " +
apk + "." + ApkTable.Cols.SIGNATURE + " = COALESCE(" + installed + "." + InstalledAppTable.Cols.SIGNATURE + ", " + apk + "." + ApkTable.Cols.SIGNATURE + ") AND " +
" ( " + app + "." + Cols.IS_COMPATIBLE + " = 0 OR " + apk + "." + ApkTable.Cols.IS_COMPATIBLE + " = 1 ) ) " +
" WHERE COALESCE(" + Cols.UPSTREAM_VERSION_CODE + ", 0) = 0 OR " + Cols.SUGGESTED_VERSION_CODE + " IS NULL ";
LoggingQuery.execSQL(db(), updateSql);
}
/**
* Limits results for an apk query. If the app in question is installed, then will limit apk
* results to those matching the same signature as the installed one. Otherwise, allows all apks
* to be returned.
*/
private static String restrictToSameSigIfInstalled(String appTable, String apkTable) {
String installedSig =
"(SELECT installed." + InstalledAppTable.Cols.SIGNATURE +
" FROM " + InstalledAppTable.NAME + " AS installed " +
" JOIN " + PackageTable.NAME + " AS pkg ON " +
" (pkg." + PackageTable.Cols.ROW_ID + " = " + appTable + "." + Cols.PACKAGE_ID + " AND " +
" installed." + InstalledAppTable.Cols.PACKAGE_ID + " = pkg." + PackageTable.Cols.ROW_ID + ") " +
")";
// Ideally, the check below would actually be written as:
// `installedSig IS NULL OR installedSig = apk.sig`
// however that would require a separate sub query for each `installedSig` which is more
// expensive. Using a COALESCE is a less expressive way to write the same thing with only
// a single subquery.
// Also note that the `installedSig IS NULL` is not because there is a `NULL` entry in the
// installed table (this is impossible), but rather because the subselect above returned
// zero rows.
return apkTable + "." + ApkTable.Cols.SIGNATURE + " = " +
"COALESCE(" + installedSig + ", " + apkTable + "." + ApkTable.Cols.SIGNATURE + ")";
}
private void updateIconUrls() {
final String appTable = getTableName();
final String apkTable = getApkTableName();

2
app/src/main/java/org/fdroid/fdroid/data/TempApkProvider.java
View File

@ -129,7 +129,7 @@ public class TempApkProvider extends ApkProvider {
final String memoryDbName = TempAppProvider.DB;
db.execSQL(DBHelper.CREATE_TABLE_APK.replaceFirst(Schema.ApkTable.NAME, memoryDbName + "." + getTableName()));
db.execSQL(TempAppProvider.copyData(Schema.ApkTable.Cols.ALL_COLS, Schema.ApkTable.NAME, memoryDbName + "." + getTableName()));
db.execSQL("CREATE INDEX IF NOT EXISTS " + memoryDbName + ".apk_vercode on " + getTableName() + " (" + ApkTable.Cols.VERSION_CODE + ");");
db.execSQL("CREATE INDEX IF NOT EXISTS " + memoryDbName + ".apk_appId on " + getTableName() + " (" + ApkTable.Cols.APP_ID + ");");
db.execSQL("CREATE INDEX IF NOT EXISTS " + memoryDbName + ".apk_compatible ON " + getTableName() + " (" + ApkTable.Cols.IS_COMPATIBLE + ");");
}