Because the way to install Oracle 19c on a SuSE Leap 15.1 is not that easy, I will give this information for other people having similar problem.

1) download SuSE Leap 15.1 from https://software.opensuse.org/distributions/leap?locale=de

2) install SuSE Leap 15.1 on a hard disk (HDD or SDD)  - I preferred to install desktop version)

3) download Oracle 19c (LINUX.X64_193000_db_home.zip - yes only zip is working for SuSE) from

    https://www.oracle.com/database/technologies/oracle-database-software-downloads.html --> "See All"

4) Prerequests (taken out of https://oracle-base.com/articles/19c/oracle-db-19c-installation-on-oracle-linux-7#manual_setup):

The "/etc/hosts" file must contain a fully qualified name for the server.

<IP-address>  <fully-qualified-machine-name>  <machine-name>

For example.

127.0.0.1       localhost localhost.localdomain localhost4 localhost4.localdomain4 
192.168.56.107  suse19.localdomain  suse19

Set the correct hostname in the "/etc/hostname" file.

suse19.localdomain

Add the following lines to the "/etc/sysctl.conf" file, or in a file called "/etc/sysctl.d/98-oracle.conf".

fs.file-max = 6815744 
kernel.sem = 250 32000 100 128 
kernel.shmmni = 4096 
kernel.shmall = 1073741824 
kernel.shmmax = 4398046511104 
kernel.panic_on_oops = 1 
net.core.rmem_default = 262144 
net.core.rmem_max = 4194304 
net.core.wmem_default = 262144 
net.core.wmem_max = 1048576 
net.ipv4.conf.all.rp_filter = 2 
net.ipv4.conf.default.rp_filter = 2 
fs.aio-max-nr = 1048576 
net.ipv4.ip_local_port_range = 9000 65500

Run one of the following commands to change the current kernel parameters, depending on which file you edited.

/sbin/sysctl -p 
# Or 
/sbin/sysctl -p /etc/sysctl.d/98-oracle.conf

Add the following lines to a file called "/etc/security/limits.d/oracle-database-preinstall-19c.conf" file.

oracle   soft   nofile    1024 
oracle   hard   nofile    65536 
oracle   soft   nproc    16384 
oracle   hard   nproc    16384 
oracle   soft   stack    10240 
oracle   hard   stack    32768 
oracle   hard   memlock    134217728 
oracle   soft   memlock    134217728

The following packages are listed as required. Many of the packages should be installed already.

==> I installed them with "yast --> software manager" not with yum - although I added to installed yum

yum install -y bc 
yum install -y binutils 
yum install -y compat-libcap1 
yum install -y compat-libstdc++-33 
#yum install -y dtrace-modules 
#yum install -y dtrace-modules-headers 
#yum install -y dtrace-modules-provider-headers 
yum install -y dtrace-utils 
yum install -y elfutils-libelf 
yum install -y elfutils-libelf-devel 
yum install -y fontconfig-devel 
yum install -y glibc 
yum install -y glibc-devel 
yum install -y ksh 
yum install -y libaio 
yum install -y libaio-devel 
yum install -y libdtrace-ctf-devel 
yum install -y libXrender 
yum install -y libXrender-devel 
yum install -y libX11 
yum install -y libXau 
yum install -y libXi 
yum install -y libXtst 
yum install -y libgcc 
yum install -y librdmacm-devel 
yum install -y libstdc++ 
yum install -y libstdc++-devel 
yum install -y libxcb 
yum install -y make 
yum install -y net-tools # Clusterware 
yum install -y nfs-utils # ACFS 
yum install -y python # ACFS 
yum install -y python-configshell # ACFS 
yum install -y python-rtslib # ACFS 
yum install -y python-six # ACFS 
yum install -y targetcli # ACFS 
yum install -y smartmontools 
yum install -y sysstat 

Create the new groups and users.

groupadd -g 54321 oinstall 
groupadd -g 54322 dba 
groupadd -g 54323 oper 
#groupadd -g 54324 backupdba 
#groupadd -g 54325 dgdba 
#groupadd -g 54326 kmdba 
#groupadd -g 54327 asmdba 
#groupadd -g 54328 asmoper
#groupadd -g 54329 asmadmin 
#groupadd -g 54330 racdba  
useradd -u 54321 -g oinstall -G dba,oper oracle

Set the password for the "oracle" user.

passwd oracle

Set secure Linux to permissive by editing the "/etc/selinux/config" file, making sure the SELINUX flag is set as follows.

(SuSE Leap 15.1 do not support SELINUX in that way that it is working fine) --> I skipped this hole option)

SELINUX=permissive

Once the change is complete, restart the server or run the following command.
# setenforce Permissive

If you have the Linux firewall enabled, you will need to disable or configure it, as shown here or here. To disable it, do the following.

# systemctl stop firewalld # systemctl disable firewalld

if you are not using Oracle Linux and UEK, you will need to manually disable transparent huge pages.

  --> https://oracle-base.com/articles/linux/configuring-huge-pages-for-oracle-on-linux-64#disabling-transparent-hugepages

create directories (my ORACLE_BASE=/opt/oracle, my ORACLE_HOME=/opt/oracle/product/ora19c/db_home1, my ORACLE_SID=ora19c, my oracle-user is "ora19c"

# export ORACLE_BASE=/opt/oracle

# export ORACLE_HOME=/opt/oracle/product/ora19c/db_home1

#

# mkdir $ORACLE_BASE

# chmod 775 $ORACLE_BASE

# chown -R oracle.oinstall $ORACLE_BASE

# xhost +<machine-name>

set ORACLE_BASE and ORACLE_HOME in ~oracle/.profile

( you can take a .profile from another installed user as template)

# su - oracle

<passwd>

$ mkdir -p  $ORACLE_HOME

$ chmod -R 775 $ORACLE_BASE

5) Run the installer as user "oracle"

su - oracle

<passwd>

./runInstaller

--> on SuSE Leap15.1 I got an error:

Prerequisite checks fails-PRVG-0282 : failed to retrieve the operating system distribution ID

  if you get this error message --> abort installation

  --> edit file "$ORACLE_HOME/cv/admin/cvu_config" and set

       "CV_ASSUME_DISTID=SUSE15" and rerun installer

5) missing packages ( I started ./runInstaller with log and debug: -logLevel finest and -debug )

    --> with debug you can see which packages are loaded and which are expected

  open another terminal and install missing packages with "yast - software manager"

  I ended up with eight missing packages - but only warnings:

  - libstdc++33-3.3.3-62.1 (solved in next option)

  - libjpeg-turbo-1.3.1

  - libjpeg62-32bit-62.1.0

  - libjpeg62-turbo-1.3.1

  - libpcre16-0-8.41 (unsolved but only warning)

  - gcc-c++-32bit-7-1.563

  - JDK-1.8.0.5.151 (unsolved but only warning)

  - libgfortran3-4.8.3 (solved in next option)

6) I found those packages for SuSE Leap 15.1 by google:

  - libgfortran3-gcc48-4.8.5-201.1.x86_64.rpm

    http://download.opensuse.org/repositories/devel:/gcc/SLE-11/x86_64/

  - libstdc++33-3.3.3-63.1.x86_64.rpm ( standalone rpm out of SLE11-Linux)

    http://rpm.pbone.net/index.php3/stat/3/srodzaj/1/search/libstdc%2B%2B.so.5%28%29%2864bit%29

7) Continue installation via runInstaller. I got an error at Listener configuration - retry and it was solved

8) Disable unused features as user oracle

cd $ORACLE_HOME/bin<br/> chopt disable oaa<br/> chopt disable olap<br/> chopt disable partitioning<br/> chopt disable rat

9) after installation of database you can continue with installation of other Oracle products

  - remember to set  CV_ASSUME_DISTID=SUSE15 " in some cvu_config" files

  --> edit file "$NEW_PRODUCT_PATH/stage/cv/admin/cvu_config" and set

       "CV_ASSUME_DISTID=SUSE15" and rerun installer