diff --git a/src/index/webqueue.cpp b/src/index/webqueue.cpp
index d8c20527..e22097fd 100644
--- a/src/index/webqueue.cpp
+++ b/src/index/webqueue.cpp
@@ -157,9 +157,8 @@ public:
         // way.  We need it because not all interesting doc fields are
         // in the meta array (ie: mimetype, url), and we want
         // something homogenous and easy to save.
-        for (map<string,string>::const_iterator it = doc.meta.begin();
-             it != doc.meta.end(); it++) {
-            m_fields.set((*it).first, (*it).second, cstr_null);
+        for (const auto& entry : doc.meta) {
+            m_fields.set(entry.first, entry.second, cstr_null);
         }
         m_fields.set(cstr_url, doc.url, cstr_null);
         m_fields.set(cstr_bgc_mimetype, doc.mimetype, cstr_null);
diff --git a/src/python/recoll/pyrecoll.cpp b/src/python/recoll/pyrecoll.cpp
index a48761f4..e5bbcd48 100644
--- a/src/python/recoll/pyrecoll.cpp
+++ b/src/python/recoll/pyrecoll.cpp
@@ -1570,8 +1570,9 @@ Db_init(recoll_DbObject *self, PyObject *args, PyObject *kwargs)
 				     &confdir, &extradbs, &writable))
 	return -1;
 
-    // If the user creates several dbs, changing the confdir, we call 
-    // recollinit repeatedly, which *should* be ok...
+    // If the user creates several dbs, changing the confdir, we call
+    // recollinit repeatedly, which *should* be ok, except that it
+    // resets the log file.
     string reason;
     delete rclconfig;
     if (confdir) {
diff --git a/src/qtgui/preview_w.cpp b/src/qtgui/preview_w.cpp
index cebc2d41..523bcadb 100644
--- a/src/qtgui/preview_w.cpp
+++ b/src/qtgui/preview_w.cpp
@@ -954,11 +954,10 @@ void PreviewTextEdit::displayFields()
         txt += "|" + QString::fromUtf8(m_ipath.c_str());
     txt += "</b><br><br>";
     txt += "<dl>\n";
-    for (map<string,string>::const_iterator it = m_fdoc.meta.begin();
-         it != m_fdoc.meta.end(); it++) {
-        if (!it->second.empty())
-            txt += "<dt>" + QString::fromUtf8(it->first.c_str()) + "</dt> " 
-                + "<dd>" + QString::fromUtf8(escapeHtml(it->second).c_str()) 
+    for (const auto& entry: m_fdoc.meta) {
+        if (!entry.second.empty())
+            txt += "<dt>" + QString::fromUtf8(entry.first.c_str()) + "</dt> " 
+                + "<dd>" + QString::fromUtf8(escapeHtml(entry.second).c_str()) 
                 + "</dd>\n";
     }
     txt += "</dl></body></html>";
diff --git a/src/qtgui/rclm_view.cpp b/src/qtgui/rclm_view.cpp
index 204b44b4..e7b38c8e 100644
--- a/src/qtgui/rclm_view.cpp
+++ b/src/qtgui/rclm_view.cpp
@@ -416,9 +416,8 @@ void RclMain::startNativeViewer(Rcl::Doc doc, int pagenum, QString term)
     subs["U"] = url_encode(url);
     subs["u"] = url;
     // Let %(xx) access all metadata.
-    for (map<string,string>::const_iterator it = doc.meta.begin();
-         it != doc.meta.end(); it++) {
-        subs[it->first] = it->second;
+    for (const auto& ent :doc.meta) {
+        subs[ent.first] = ent.second;
     }
     execViewer(subs, enterHistory, execpath, lcmd, cmd, doc, execwflags);
 }
diff --git a/src/qtgui/restable.cpp b/src/qtgui/restable.cpp
index e5a92cba..49a95f0a 100644
--- a/src/qtgui/restable.cpp
+++ b/src/qtgui/restable.cpp
@@ -162,7 +162,7 @@ void ResTableDetailArea::createPopupMenu(const QPoint& pos)
 // little processing
 static string gengetter(const string& fld, const Rcl::Doc& doc)
 {
-    map<string, string>::const_iterator it = doc.meta.find(fld);
+    const auto it = doc.meta.find(fld);
     if (it == doc.meta.end()) {
 	return string();
     }
@@ -171,7 +171,7 @@ static string gengetter(const string& fld, const Rcl::Doc& doc)
 
 static string sizegetter(const string& fld, const Rcl::Doc& doc)
 {
-    map<string, string>::const_iterator it = doc.meta.find(fld);
+    const auto it = doc.meta.find(fld);
     if (it == doc.meta.end()) {
 	return string();
     }
diff --git a/src/query/recollq.cpp b/src/query/recollq.cpp
index f38e814a..e2483f07 100644
--- a/src/query/recollq.cpp
+++ b/src/query/recollq.cpp
@@ -61,8 +61,8 @@ void output_fields(vector<string> fields, Rcl::Doc& doc,
 {
     if (fields.empty()) {
         map<string,string>::const_iterator it;
-        for (it = doc.meta.begin();it != doc.meta.end(); it++) {
-            fields.push_back(it->first);
+        for (const auto& entry : doc.meta) {
+            fields.push_back(entry.first);
         }
     }
     for (vector<string>::const_iterator it = fields.begin();
@@ -406,9 +406,8 @@ endopts:
 		<< doc.fbytes << "\tbytes" << "\t"
 		<<  endl;
 	    if (op_flags & OPT_m) {
-		for (map<string,string>::const_iterator it = doc.meta.begin();
-		     it != doc.meta.end(); it++) {
-		    cout << it->first << " = " << it->second << endl;
+		for (const auto ent : doc.meta) {
+		    cout << ent.first << " = " << ent.second << endl;
 		}
 	    }
             if (op_flags & OPT_A) {
diff --git a/src/query/reslistpager.cpp b/src/query/reslistpager.cpp
index 34f8512b..95208444 100644
--- a/src/query/reslistpager.cpp
+++ b/src/query/reslistpager.cpp
@@ -313,10 +313,9 @@ void ResListPager::displayDoc(RclConfig *config, int i, Rcl::Doc& doc,
     subs["x"] = xdocidbuf;
     
     // Let %(xx) access all metadata. HTML-neuter everything:
-    for (map<string,string>::iterator it = doc.meta.begin(); 
-	 it != doc.meta.end(); it++) {
-	if (!it->first.empty()) 
-	    subs[it->first] = maybeEscapeHtml(it->second);
+    for (const auto& entry : doc.meta) {
+	if (!entry.first.empty()) 
+	    subs[entry.first] = maybeEscapeHtml(entry.second);
     }
 
     string formatted;
diff --git a/src/query/sortseq.cpp b/src/query/sortseq.cpp
index e7822c36..1bbc1a2e 100644
--- a/src/query/sortseq.cpp
+++ b/src/query/sortseq.cpp
@@ -32,9 +32,8 @@ public:
     { 
 	LOGDEB1("Comparing .. \n" );
 
-	map<string,string>::const_iterator xit, yit;
-	xit = x->meta.find(ss.field);
-	yit = y->meta.find(ss.field);
+	const auto xit = x->meta.find(ss.field);
+	const auto yit = y->meta.find(ss.field);
 	if (xit == x->meta.end() || yit == y->meta.end())
 	    return 0;
 	return ss.desc ? yit->second < xit->second : xit->second < yit->second;
diff --git a/src/rcldb/rcldb.cpp b/src/rcldb/rcldb.cpp
index bf9da701..96642c15 100644
--- a/src/rcldb/rcldb.cpp
+++ b/src/rcldb/rcldb.cpp
@@ -1885,21 +1885,21 @@ bool Db::Native::docToXdocXattrOnly(TextSplitDb *splitter, const string &udi,
 
     // Clear the term lists for the incoming fields and index the new values
     map<string, string>::iterator meta_it;
-    for (meta_it = doc.meta.begin(); meta_it != doc.meta.end(); meta_it++) {
+    for (const auto& ent : doc.meta) {
 	const FieldTraits *ftp;
-	if (!m_rcldb->fieldToTraits(meta_it->first, &ftp) || ftp->pfx.empty()) {
+	if (!m_rcldb->fieldToTraits(ent.first, &ftp) || ftp->pfx.empty()) {
 	    LOGDEB0("Db::xattrOnly: no prefix for field [" <<
-                    meta_it->first << "], skipped\n");
+                    ent.first << "], skipped\n");
 	    continue;
 	}
 	// Clear the previous terms for the field
 	clearField(xdoc, ftp->pfx, ftp->wdfinc);
-	LOGDEB0("Db::xattrOnly: field [" << meta_it->first << "] pfx [" <<
+	LOGDEB0("Db::xattrOnly: field [" << ent.first << "] pfx [" <<
                 ftp->pfx << "] inc " << ftp->wdfinc << ": [" <<
-                meta_it->second << "]\n");
+                ent.second << "]\n");
 	splitter->setTraits(*ftp);
-	if (!splitter->text_to_words(meta_it->second)) {
-	    LOGDEB("Db::xattrOnly: split failed for " << meta_it->first << "\n");
+	if (!splitter->text_to_words(ent.second)) {
+	    LOGDEB("Db::xattrOnly: split failed for " << ent.first << "\n");
         }
     }
     xdoc.add_value(VALUE_SIG, doc.sig);
diff --git a/src/rcldb/rcldoc.h b/src/rcldb/rcldoc.h
index a36e174c..4f7325f0 100644
--- a/src/rcldb/rcldoc.h
+++ b/src/rcldb/rcldoc.h
@@ -18,7 +18,7 @@
 #define _RCLDOC_H_INCLUDED_
 
 #include <string>
-#include <map>
+#include <unordered_map>
 #include <vector>
 
 #include "smallut.h"
@@ -79,7 +79,7 @@ public:
     // Only some predefined fields are stored in the data record:
     // "title", "keywords", "abstract", "author", but if a field name is
     // in the "stored" configuration list, it will be stored too.
-    std::map<std::string, std::string> meta; 
+    std::unordered_map<std::string, std::string> meta; 
 
     // Attribute for the "abstract" entry. true if it is just the top
     // of doc, not a native document attribute. Not stored directly, but
diff --git a/src/utils/rclutil.cpp b/src/utils/rclutil.cpp
index 653cdae2..08fa522e 100644
--- a/src/utils/rclutil.cpp
+++ b/src/utils/rclutil.cpp
@@ -37,6 +37,8 @@
 #include "safesysstat.h"
 
 #include <mutex>
+#include <map>
+#include <unordered_map>
 
 #include "rclutil.h"
 #include "pathut.h"
@@ -49,15 +51,18 @@
 using namespace std;
 
 
-void map_ss_cp_noshr(const map<string, string> s, map<string, string> *d)
+template <class T> void map_ss_cp_noshr(T s, T *d)
 {
-    for (map<string, string>::const_iterator it = s.begin();
-            it != s.end(); it++) {
+    for (const auto& ent : s) {
         d->insert(
-            pair<string, string>(string(it->first.begin(), it->first.end()),
-                                 string(it->second.begin(), it->second.end())));
+            pair<string, string>(string(ent.first.begin(), ent.first.end()),
+                                 string(ent.second.begin(), ent.second.end())));
     }
 }
+template void map_ss_cp_noshr<map<string, string> >(
+    map<string, string> s, map<string, string>*d);
+template void map_ss_cp_noshr<unordered_map<string, string> >(
+    unordered_map<string,string> s, unordered_map<string,string>*d);
 
 #ifdef _WIN32
 static bool path_hasdrive(const string& s)
diff --git a/src/utils/rclutil.h b/src/utils/rclutil.h
index f4cb93b5..e5c9e5fc 100644
--- a/src/utils/rclutil.h
+++ b/src/utils/rclutil.h
@@ -94,10 +94,9 @@ private:
 extern bool thumbPathForUrl(const std::string& url, int size,
                             std::string& path);
 
-// Duplicate map<string,string> while ensuring no shared string data (to pass
-// to other thread):
-void map_ss_cp_noshr(const std::map<std::string, std::string> s,
-                     std::map<std::string, std::string> *d);
+// Duplicate (unordered)map<string,string> while ensuring no shared
+// string data (to pass to other thread):
+template <class T> void map_ss_cp_noshr(T s, T *d);
 
 
 #endif /* _RCLUTIL_H_INCLUDED_ */